function fillCategory()
{ 
	// This function is used to fill the category list on load
	addOption(document.order.Category, "Mechanics", "Mechanics", "");
	addOption(document.order.Category, "Periodic Motion", "Periodic Motion", "");
	addOption(document.order.Category, "Waves", "Waves", "");
	addOption(document.order.Category, "Optics", "Optics", "");
	addOption(document.order.Category, "Fluids", "Fluids", "");
	addOption(document.order.Category, "Heat", "Heat", "");
	addOption(document.order.Category, "Thermodynamics", "Thermodynamics", "");
	addOption(document.order.Category, "Electrostatics", "Electrostatics", "");
	addOption(document.order.Category, "Capacitors", "Capacitors", "");
	addOption(document.order.Category, "Electricity", "Electricity", "");
	addOption(document.order.Category, "Magnetostatistics", "Magnetostatistics", "");
	addOption(document.order.Category, "Electromagnetics", "Electromagnetics", "");
	addOption(document.order.Category, "Modern Physics", "Modern Physics", "");
}

function SelectSubCat()
{
	// ON selection of category this function will work
	removeAllOptions(document.order.SubCat);
	addOption(document.order.SubCat, "", "SubCat", "");

	if(document.order.Category.value == "Mechanics")
	{
		addOption(document.order.SubCat, "Demonstration Set", "Demonstration Set");
		addOption(document.order.SubCat, "Vector Addition", "Vector Addition");
		addOption(document.order.SubCat, "Center of Mass", "Center of Mass");
		addOption(document.order.SubCat, "Newton's 1st Law", "Newton's 1st Law");
		addOption(document.order.SubCat, "Newton's 2nd Law", "Newton's 2nd Law");
		addOption(document.order.SubCat, "Newton's 3rd Law", "Newton's 3rd Law");
		addOption(document.order.SubCat, "Gravitation", "Gravitation");
		addOption(document.order.SubCat, "Conservation` of Linear Momentum", "Coservation of Linear Momentum");
		addOption(document.order.SubCat, "Conservation of Mechanical Energy", "Conservation of Mechanical Energy");
		addOption(document.order.SubCat, "Torque", "Torque");
		addOption(document.order.SubCat, "Friction", "Friction");
		addOption(document.order.SubCat, "Centripetal Force", "Centripetal Force");
		addOption(document.order.SubCat, "Rotational Motion", "Rotational Motion");
		addOption(document.order.SubCat, "Conservation of Angular Momentum", "Conservation of Angular Momentum");
		addOption(document.order.SubCat, "Gyroscope", "Gyroscope");
	}

	if(document.order.Category.value == "Periodic Motion")
	{
		addOption(document.order.SubCat, "Simple Harmonic Motion", "Simple Harmonic Motion");
	}

	if(document.order.Category.value == "Waves")
	{
		addOption(document.order.SubCat, "Wave Motion", "Wave Motion");
		addOption(document.order.SubCat, "Standing Waves", "Standing Waves");
		addOption(document.order.SubCat, "Sound Waves", "Sound Waves");
		addOption(document.order.SubCat, "Interference", "Interference");
		addOption(document.order.SubCat, "Resonance", "Resonance");
		addOption(document.order.SubCat, "Beats", "Beats");
		addOption(document.order.SubCat, "Doppler Effect", "Doppler Effect");
	}

	if(document.order.Category.value == "Optics")
	{
		addOption(document.order.SubCat, "Reflection, Refraction and Dispersion", "Reflection, Refraction and Dispersion");
		addOption(document.order.SubCat, "Interference and Diffraction", "Interference and Diffraction");
		addOption(document.order.SubCat, "Mirrors", "Mirrors");
		addOption(document.order.SubCat, "Polarization", "Polarization");
		addOption(document.order.SubCat, "Colors", "Colors");
		addOption(document.order.SubCat, "Holograms", "Holograms");
		addOption(document.order.SubCat, "Solar Energy", "Solar Energy");
	}

	if(document.order.Category.value == "Fluids")
	{
		addOption(document.order.SubCat, "Atmospheric and Hydrostatic Pressure", "Atmospheric and Hydrostatic Pressure");
		addOption(document.order.SubCat, "Pascal's Principle", "Pascal's Principle");
		addOption(document.order.SubCat, "Archimede's Principle", "Archimede's Principle");
		addOption(document.order.SubCat, "Buoyancy and Density", "Buoyancy and Density");
		addOption(document.order.SubCat, "Surface Tension", "Surface Tension");
		addOption(document.order.SubCat, "Non-Newtonian Fluids", "Non-Newtonian Fluids");
		addOption(document.order.SubCat, "Bernoulli's Theorem", "Bernoulli's Theorem");
		addOption(document.order.SubCat, "Convection", "Convection");
		addOption(document.order.SubCat, "Temprature Dependence on Water Density - Density Ball", "Temprature Dependence on Water Density - Density Ball");
	}

	if(document.order.Category.value == "Heat")
	{
		addOption(document.order.SubCat, "Heat Radiation, Absorption and Reflection", "Heat Radiation, Absorption and Reflection");
		addOption(document.order.SubCat, "Thermal Expansion", "Thermal Expansion");
		addOption(document.order.SubCat, "Heat Conductivity", "Heat Conductivity");
		addOption(document.order.SubCat, "Specific Heat", "Specific Heat");
		addOption(document.order.SubCat, "Lava Lite Lamp", "Lava Lite Lamp");
	}

	if(document.order.Category.value == "Thermodynamics")
	{
		addOption(document.order.SubCat, "Change of State", "Change of State");
		addOption(document.order.SubCat, "Mechanical Equivalent of Heat", "Mechanical Equivalent of Heat");
		addOption(document.order.SubCat, "Thermal Behavior of Gases", "Thermal Behavior of Gases");
		addOption(document.order.SubCat, "Joule Thompson Model", "Joule Thompson Model");
		addOption(document.order.SubCat, "Engine Models", "Engine Models");
		addOption(document.order.SubCat, "Thermocouple", "Thermocouple");
	}

	if(document.order.Category.value == "Electrostatics")
	{
		addOption(document.order.SubCat, "Attraction, Repulsion and Induction", "Attraction, Repulsion and Induction");
		addOption(document.order.SubCat, "Wimshurst Static Machine and Accessories", "Wimshurst Static Machine and Accessories");
		addOption(document.order.SubCat, "Van De Graaff Generator", "Van De Graaff Generator");
		addOption(document.order.SubCat, "Gauss' Law", "Gauss' Law");
	}

	if(document.order.Category.value == "Capacitors")
	{
		addOption(document.order.SubCat, "Parallel State Capacitor", "Parallel State Capacitor");
		addOption(document.order.SubCat, "Paper, electrolytic and Variable Capacitors", "Paper, electrolytic and Variable Capacitors");
		addOption(document.order.SubCat, "Dissectable Leyden Jar", "Dissectable Leyden Jar");
		addOption(document.order.SubCat, "Energy in a Capacitor", "Energy in a Capacitor");
		addOption(document.order.SubCat, "RC Time Constant", "RC Time Constant");
	}

	if(document.order.Category.value == "Electricity")
	{
		addOption(document.order.SubCat, "Lamp Board", "Lamp Board");
		addOption(document.order.SubCat, "Resistors in Series and Parallel", "Resistors in Series and Parallel");
		addOption(document.order.SubCat, "Piezoelectric Demonstrator", "Piezoelectric Demonstrator");
		addOption(document.order.SubCat, "Thermocouple", "Thermocouple");
		addOption(document.order.SubCat, "Solar Radiation and Electrical Current", "Solar Radiation and Electrical Current");
		addOption(document.order.SubCat, "Conductivity of a Solution", "Conductivity of a Solution");
		addOption(document.order.SubCat, "DC Measurements", "DC Measurements");
	}

	if(document.order.Category.value == "Magnetostatistics")
	{
		addOption(document.order.SubCat, "Magnetic Field", "Magnetic Field");
		addOption(document.order.SubCat, "Floating Magnets", "Floating Magnets");
		addOption(document.order.SubCat, "Magnetic Poles", "Magnetic Poles");
		addOption(document.order.SubCat, "Magnetic Poles", "Magnetic Poles");
		addOption(document.order.SubCat, "Domains", "Domains");
		addOption(document.order.SubCat, "Magnetic Dip Needle", "Magnetic Dip Needle");
	}

	if(document.order.Category.value == "Electromagnetics")
	{
		addOption(document.order.SubCat, "Magnetic Effects of Current", "Magnetic Effects of Current");
		addOption(document.order.SubCat, "Induced Current", "Induced Current");
		addOption(document.order.SubCat, "Transformers", "Transformers");
		addOption(document.order.SubCat, "Force Between Parallel Current-Carrying Conductors", "Force Between Parallel Current-Carrying Conductors");
		addOption(document.order.SubCat, "Eddy Current", "Eddy Current");
		addOption(document.order.SubCat, "Current in a Magnetic Field", "Current in a Magnetic Field");
		addOption(document.order.SubCat, "Electric Generator", "Electric Generator");
		addOption(document.order.SubCat, "Galvanometer", "Galvanometer");
		addOption(document.order.SubCat, "LRC Circuits", "LRC Circuits");
		addOption(document.order.SubCat, "Hertzian Waves", "Hertzian Waves");
		addOption(document.order.SubCat, "Resistance of Conductors", "Resistance of Conductors");
	}

	if(document.order.Category.value == "Modern Physics")
	{
		addOption(document.order.SubCat, "Cathode Ray Tubes", "Cathode Ray Tubes");
		addOption(document.order.SubCat, "Electron Motion in a Uniform Magnetic Field", "Electron Motion in a Uniform Magnetic Field");
		addOption(document.order.SubCat, "Crystal Structure", "Crystal Structure");
		addOption(document.order.SubCat, "Electron Diffraction", "Electron Diffraction");
		addOption(document.order.SubCat, "Radioactivity", "Radioactivity");
		addOption(document.order.SubCat, "Superconductivity", "Superconductivity");
		addOption(document.order.SubCat, "Fluorescent Liquids Set", "Fluorescent Liquids Set");
	}
}

function SelectDemo()
{
	// ON selection of category this function will work
	removeAllOptions(document.order.Demo);
	addOption(document.order.Demo, "", "Demo", "");

	if(document.order.SubCat.value == "Demonstration Set")
	{
		addOption(document.order.Demo, "M.1 - Blackboard Mechanics", "M.1 - Blackboard Mechanics");
	}

	if(document.order.SubCat.value == "Vector Addition")
	{
		addOption(document.order.Demo, "M.2(1) - Force Table", "M.2(1) - Force Table");
		addOption(document.order.Demo, "M.2(2) - Fan Cart", "M.2(2) - Fan Cart");
		addOption(document.order.Demo, "M.2(3) - Perpendicular Component", "M.2(3) - Perpendicular Component");
	}

	if(document.order.SubCat.value == "Center of Mass")
	{
		addOption(document.order.Demo, "M.3(1) - Leaning Tower of Pisa", "M.3(1) - Leaning Tower of Pisa");
		addOption(document.order.Demo, "M.3(2) - Double Cone and Inclined Plane", "M.3(2) - Double Cone and Inclined Plane");
		addOption(document.order.Demo, "M.3(3) - Center of Mass Apparatus", "M.3(3) - Center of Mass Apparatus");
		addOption(document.order.Demo, "M.3(4) - Finding the Center of Gravity", "M.3(4) - Finding the Center of Gravity");
		addOption(document.order.Demo, "M.3(5) - Cyclist Riding on a Wire", "M.3(5) - Cyclist Riding on a Wire");
		addOption(document.order.Demo, "M.3(6) - Pendulum on the Cart", "M.3(6) - Pendulum on the Cart");
		addOption(document.order.Demo, "M.3(7) - Center of Gravity Paradox", "M.3(7) - Center of Gravity Paradox");
		addOption(document.order.Demo, "M.3(8) - The Feeble-Minded Disc", "M.3(8) - The Feeble-Minded Disc");
		addOption(document.order.Demo, "M.3(9) - The Plastic Bird", "M.3(9) - The Plastic Bird");
	}

	if(document.order.SubCat.value == "Newton's 1st Law")
	{
		addOption(document.order.Demo, "M.4(1) - Dishes on a Tablecloth", "M.4(1) - Dishes on a Tablecloth");
		addOption(document.order.Demo, "M.4(2) - Flipping the Card", "M.4(2) - Flipping the Card");
		addOption(document.order.Demo, "M.4(3) - Inertia Appratus", "M.4(3) - Inertia Appratus");
		addOption(document.order.Demo, "M.4(4) - Lead Brick - Inertia Demonstration", "M.4(4) - Lead Brick - Inertia Demonstration");
		addOption(document.order.Demo, "M.4(5) - Loaded Cart Pulled by a String", "M.4(5) - Loaded Cart Pulled by a String");
		addOption(document.order.Demo, "M.4(6) - Bed of Nails", "M.4(6) - Bed of Nails");
		addOption(document.order.Demo, "M.4(7) - Intermediate Momentum of Inertia", "M.4(7) - Intermediate Momentum of Inertia");
	}

	if(document.order.SubCat.value == "Newton's 2nd Law")
	{
		addOption(document.order.Demo, "M.5(1a) - Shooting and Dropping a Ball", "M.5(1a) - Shooting and Dropping a Ball");
		addOption(document.order.Demo, "M.5(1b) - Ballistic Cart", "M.5(1b) - Ballistic Cart");
		addOption(document.order.Demo, "M.5(1c) - Water Stream Parabola	", "M.5(1c) - Water Stream Parabola	");
		addOption(document.order.Demo, "M.5(1d) - The Bear and the Hunter Demonstration", "M.5(1d) - The Bear and the Hunter Demonstration");
		addOption(document.order.Demo, "M.5(1e) - Center of Mass Rod", "M.5(1e) - Center of Mass Rod");
		addOption(document.order.Demo, "M.5(2a) - Air Track", "M.5(2a) - Air Track");
		addOption(document.order.Demo, "M.5(2b) - Accelerating Glider", "M.5(2b) - Accelerating Glider");
		addOption(document.order.Demo, "M.5(2c) - Cart on Inclined Plane", "M.5(2c) - Cart on Inclined Plane");
		addOption(document.order.Demo, "M.5(2d) - Air Table", "M.5(2d) - Air Table");
	}

	if(document.order.SubCat.value == "Newton's 3rd Law")							
	{
		addOption(document.order.Demo, "M.6(1) - Fan Cart", "M.6(1) - Fan Cart");
		addOption(document.order.Demo, "M.6(2) - Action and Reaction", "M.6(2) - Action and Reaction");
		addOption(document.order.Demo, "M.6(3) - Paradox of Forces", "M.6(3) - Paradox of Forces");
		addOption(document.order.Demo, "M.6(4) - Reaction Carts", "M.6(4) - Reaction Carts");
		addOption(document.order.Demo, "M.6(5) - Magnets on a Balance", "M.6(5) - Magnets on a Balance");
		addOption(document.order.Demo, "M.6(6) - Hero's Jet Engine", "M.6(6) - Hero's Jet Engine");
		addOption(document.order.Demo, "M.6(7) - CO2 Rocket - The Rocket Propulsion Demonstrator", "M.6(7) - CO2 Rocket - The Rocket Propulsion Demonstrator");
		addOption(document.order.Demo, "M.6(8) - Jet Propulsion", "M.6(8) - Jet Propulsion");
	}

	if(document.order.SubCat.value == "Gravitation")								
	{
		addOption(document.order.Demo, "M.7(1) - Coin and Feather Tube", "M.7(1) - Coin and Feather Tube");
		addOption(document.order.Demo, "M.7(2) - Atwood Machine", "M.7(2) - Atwood Machine");
		addOption(document.order.Demo, "M.7(3) - Falling Body Experiment", "M.7(3) - Falling Body Experiment");
		addOption(document.order.Demo, "M.7(4) - Hinged Stick and Falling Ball", "M.7(4) - Hinged Stick and Falling Ball");
	}

	if(document.order.SubCat.value == "Conservation of Linear Momentum")				
	{
		addOption(document.order.Demo, "M.8(1) - Small Reaction Carts", "M.8(1) - Small Reaction Carts");
		addOption(document.order.Demo, "M.8(2) - Large Reaction Carts", "M.8(2) - Large Reaction Carts");
		addOption(document.order.Demo, "M.8(3) - Jet Propulsion", "M.8(3) - Jet Propulsion");
		addOption(document.order.Demo, "M.8(4) - Super Ball Collision Set", "M.8(4) - Super Ball Collision Set");
		addOption(document.order.Demo, "M.8(5) - Collision Ball Apparatus", "M.8(5) - Collision Ball Apparatus");
		addOption(document.order.Demo, "M.8(6) - Dead Ball - Live Ball", "M.8(6) - Dead Ball - Live Ball");
	}

	if(document.order.SubCat.value == "Conservation of Mechanical Energy")			
	{
		addOption(document.order.Demo, "M.9(1) - Bowling Ball Pendulum", "M.9(1) - Bowling Ball Pendulum");
		addOption(document.order.Demo, "M.9(2) - Loop-the-Loop", "M.9(2) - Loop-the-Loop");
		addOption(document.order.Demo, "M.9(3) - Energy of Rotation", "M.9(3) - Energy of Rotation");
		addOption(document.order.Demo, "M.9(4) - Ballistic Pendulum", "M.9(4) - Ballistic Pendulum");
		addOption(document.order.Demo, "M.9(5) - High Road - Low Road", "M.9(5) - High Road - Low Road");
		addOption(document.order.Demo, "M.9(6) - Interrupted Pendulum", "M.9(6) - Interrupted Pendulum");
	}

	if(document.order.SubCat.value == "Torque")										
	{
		addOption(document.order.Demo, "M.10(1) - Simple Lever", "M.10(1) - Simple Lever");
		addOption(document.order.Demo, "M.10(2) - Torque Demonstration", "M.10(2) - Torque Demonstration");
		addOption(document.order.Demo, "M.10(3) - Maxwell's Wheel - Rolling Spool", "M.10(3) - Maxwell's Wheel - Rolling Spool");
	}

	if(document.order.SubCat.value == "Friction")									
	{
		addOption(document.order.Demo, "M.11 - Friction Blocks", "M.11 - Friction Blocks");
	}

	if(document.order.SubCat.value == "Centripetal Force")							
	{
		addOption(document.order.Demo, "M.12(1) - Centripetal Hoop", "M.12(1) - Centripetal Hoop");
		addOption(document.order.Demo, "M.12(2) - Rotator Globe", "M.12(2) - Rotator Globe");
		addOption(document.order.Demo, "M.12(3) - Loop-The-Loop", "M.12(3) - Loop-The-Loop");
		addOption(document.order.Demo, "M.12(4) - Centripetal Force Appratus #1", "M.12(4) - Centripetal Force Appratus #1");
	}

	if(document.order.SubCat.value == "Rotational Motion")							
	{
		addOption(document.order.Demo, "M.13(1) - Moment of Inertia of a Disk and a Ring", "M.13(1) - Moment of Inertia of a Disk and a Ring");
		addOption(document.order.Demo, "M.13(2) - Axis of Rotation", "M.13(2) - Axis of Rotation");
		addOption(document.order.Demo, "M.13(3) - Rolling and Sliding - Energy of Rotation", "M.13(3) - Rolling and Sliding - Energy of Rotation");
		addOption(document.order.Demo, "M.13(4) - Falling Ball and Hinged Stic", "M.13(4) - Falling Ball and Hinged Stic");
		addOption(document.order.Demo, "M.13(5) - The Aberrant Candle Flame", "M.13(5) - The Aberrant Candle Flame");
		addOption(document.order.Demo, "M.13(6) - Moment of Inertia Apparatus", "M.13(6) - Moment of Inertia Apparatus");
	}

	if(document.order.SubCat.value == "Conservation of Angular Momentum")			
	{
		addOption(document.order.Demo, "M.14(1) - Rotating Platform and Dumbbells", "M.14(1) - Rotating Platform and Dumbbells");
		addOption(document.order.Demo, "M.14(2) - Bicycle Wheel Gyroscope", "M.14(2) - Bicycle Wheel Gyroscope");
		addOption(document.order.Demo, "M.14(3) - Tippe-Top", "M.14(3) - Tippe-Top");
		addOption(document.order.Demo, "M.14(4) - Governor", "M.14(4) - Governor");
		addOption(document.order.Demo, "M.14(5) - Rotation of a Non-Homogenous Sphere", "M.14(5) - Rotation of a Non-Homogenous Sphere");
	}

	if(document.order.SubCat.value == "Gyroscope")									
	{
		addOption(document.order.Demo, "M.15(1) - Large Demonstration Gyroscope", "M.15(1) - Large Demonstration Gyroscope");
		addOption(document.order.Demo, "M.15(2) - Demonstration Gyroscope", "M.15(2) - Demonstration Gyroscope");
		addOption(document.order.Demo, "M.15(3) - Gyroscope with Gimbal Rings", "M.15(3) - Gyroscope with Gimbal Rings");
		addOption(document.order.Demo, "M.15(4) - Air-Bearing Gyroscope", "M.15(4) - Air-Bearing Gyroscope");
		addOption(document.order.Demo, "M.15(5) - Bicycle Wheel Gyroscope", "M.15(5) - Bicycle Wheel Gyroscope");
		addOption(document.order.Demo, "M.15(6) - Maxwell Top", "M.15(6) - Maxwell Top");
	}


	if(document.order.SubCat.value == "Simple Harmonic Motion")						
	{
		addOption(document.order.Demo, "P.1(1) - Simple Harmonic Oscillator", "P.1(1) - Simple Harmonic Oscillator");
		addOption(document.order.Demo, "P.1(2) - Simple Pendulum", "P.1(2) - Simple Pendulum");
		addOption(document.order.Demo, "P.1(3) - Sine Wave Recorder", "P.1(3) - Sine Wave Recorder");
		addOption(document.order.Demo, "P.1(4) - Relationship Between SHM and Uniform Circular Motion", "P.1(4) - Relationship Between SHM and Uniform Circular Motion");
		addOption(document.order.Demo, "P.1(5) - Compound Pendulum", "P.1(5) - Compound Pendulum");
		addOption(document.order.Demo, "P.1(6) - Inverted Pendulum", "P.1(6) - Inverted Pendulum");
		addOption(document.order.Demo, "P.1(7) - Wilbur Pendulum", "P.1(7) - Wilbur Pendulum");
		addOption(document.order.Demo, "P.1(8) - Torsion Pendulum", "P.1(8) - Torsion Pendulum");
	}

	if(document.order.SubCat.value == "Wave Motion")								
	{
		addOption(document.order.Demo, "W.1 (1) - Large Transversal Wave Machine", "W.1 (1) - Large Transversal Wave Machine");
		addOption(document.order.Demo, "W.1 (2) - Longitudinal Wave Machine", "W.1 (2) - Longitudinal Wave Machine");
		addOption(document.order.Demo, "W.1 (3) - Rubber Rope", "W.1 (3) - Rubber Rope");
		addOption(document.order.Demo, "W.1 (4) - Tuning Fork with Stylus", "W.1 (4) - Tuning Fork with Stylus");
	}

	if(document.order.SubCat.value == "Standing Waves")								
	{
		addOption(document.order.Demo, "W.2(1) - Vibrations in a String - Melde's Experiment", "W.2(1) - Vibrations in a String - Melde's Experiment");
		addOption(document.order.Demo, "W.2(2) - Standing Wave Across Two Different Mediums", "W.2(2) - Standing Wave Across Two Different Mediums");
		addOption(document.order.Demo, "W.2(3) - Chladni's Sand Figures", "W.2(3) - Chladni's Sand Figures");
	}

	if(document.order.SubCat.value == "Sound Waves")								
	{
		addOption(document.order.Demo, "W.3(1) - Organ Pipes", "W.3(1) - Organ Pipes");
		addOption(document.order.Demo, "W.3(2) - Electric Buzzer in Vacuum", "W.3(2) - Electric Buzzer in Vacuum");
		addOption(document.order.Demo, "W.3(3) - Resonance Apparatus", "W.3(3) - Resonance Apparatus");
	}

	if(document.order.SubCat.value == "Interference")								
	{
		addOption(document.order.Demo, "W.4(1) - Ripple Tank", "W.4(1) - Ripple Tank");
		addOption(document.order.Demo, "W.4(2) - Phase Difference Wave Machine", "W.4(2) - Phase Difference Wave Machine");
	}

	if(document.order.SubCat.value == "Resonance")									
	{
		addOption(document.order.Demo, "W.5(1) - Sympathetic Tuning Forks", "W.5(1) - Sympathetic Tuning Forks");
		addOption(document.order.Demo, "W.5(2) - Resonance Apparatus", "W.5(2) - Resonance Apparatus");
		addOption(document.order.Demo, "W.5(4) - ME-311 Resonance Demonstrator", "W.5(4) - ME-311 Resonance Demonstrator");
	}

	if(document.order.SubCat.value == "Beats")										
	{
		addOption(document.order.Demo, "W.6(1) - Tuning Forks", "W.6(1) - Tuning Forks");
	}

	if(document.order.SubCat.value == "Doppler Effect")				
	{
		addOption(document.order.Demo, "W.8(1) - Ripple Tank", "W.8(1) - Ripple Tank");
		addOption(document.order.Demo, "W.8(2) - Swinging a Tuning Fork", "W.8(2) - Swinging a Tuning Fork");
		addOption(document.order.Demo, "W.8(3) - Spinning Whistle", "W.8(3) - Spinning Whistle");
		addOption(document.order.Demo, "W.8(4) - Doppler Rocket", "W.8(4) - Doppler Rocket");
	}

	if(document.order.SubCat.value == "Reflection, Refraction and Dispersion")		
	{
		addOption(document.order.Demo, "O.1 (1) Ray Optics Laser System", "O.1 (1) Ray Optics Laser System");
		addOption(document.order.Demo, "0.1 (2) Optical Disk", "0.1 (2) Optical Disk");
		addOption(document.order.Demo, "O.1 (3) Refraction Tank", "O.1 (3) Refraction Tank");
		addOption(document.order.Demo, "0.1 (4) Total Internal Reflection", "0.1 (4) Total Internal Reflection");
		addOption(document.order.Demo, "0.1 (5) Lenses", "0.1 (5) Lenses");
		addOption(document.order.Demo, "0.1 (6) Prism", "0.1 (6) Prism");
		addOption(document.order.Demo, "O.1 (7) Disappearing Beaker", "O.1 (7) Disappearing Beaker");
	}

	if(document.order.SubCat.value == "Interference and Diffraction")				
	{
		addOption(document.order.Demo, "O.2 (1) - Projection of Grating Spectra", "O.2 (1) - Projection of Grating Spectra");
		addOption(document.order.Demo, "0.2 (2) - Different Gases Spectrum", "0.2 (2) - Different Gases Spectrum");
		addOption(document.order.Demo, "0.2 (3) - Newton's Ring Apparatus", "0.2 (3) - Newton's Ring Apparatus");
		addOption(document.order.Demo, "0.2 (4) - Interference Model", "0.2 (4) - Interference Model");
		addOption(document.order.Demo, "0.2 (5) - Single and Double Slit Diffraction Patterns", "0.2 (5) - Single and Double Slit Diffraction Patterns");
		addOption(document.order.Demo, "0.2 (6) - Other Diffraction Patterns", "0.2 (6) - Other Diffraction Patterns");
		addOption(document.order.Demo, "0.2 (7) - Diffraction Grating Model", "0.2 (7) - Diffraction Grating Model");
		addOption(document.order.Demo, "0.2 (8) - Young's Double Slit Apparatus", "0.2 (8) - Young's Double Slit Apparatus");
	}

	if(document.order.SubCat.value == "Mirrors")									
	{
		addOption(document.order.Demo, "O.3 (1a) Suspended Ball", "O.3 (1a) Suspended Ball");
		addOption(document.order.Demo, "0.3 (1b) Illusion", "0.3 (1b) Illusion");
		addOption(document.order.Demo, "0.3 (2) Two Mirrors - Multiple Images", "0.3 (2) Two Mirrors - Multiple Images");
		addOption(document.order.Demo, "0.3 (3a) Candle Burning at Both Ends", "0.3 (3a) Candle Burning at Both Ends");
		addOption(document.order.Demo, "0.3 (3b) Spherical Aberration for a Mirror", "0.3 (3b) Spherical Aberration for a Mirror");
	}

	if(document.order.SubCat.value == "Polarization")								
	{
		addOption(document.order.Demo, "O.4 (1) Polarizing Filters", "O.4 (1) Polarizing Filters");
		addOption(document.order.Demo, "0.4 (2) Double Refraction", "0.4 (2) Double Refraction");
		addOption(document.order.Demo, "0.4 (3) Brewster's Angle: Polarization by Reflection", "0.4 (3) Brewster's Angle: Polarization by Reflection");
		addOption(document.order.Demo, "0.4 (4) Red Sunset Experiment", "0.4 (4) Red Sunset Experiment");
	}

	if(document.order.SubCat.value == "Colors")										
	{
		addOption(document.order.Demo, "O.5 (1) Color Box", "O.5 (1) Color Box");
		addOption(document.order.Demo, "0.5 (2) Subtractive Color Mixing", "0.5 (2) Subtractive Color Mixing");
		addOption(document.order.Demo, "0.5 (3) Newton's Color Disk", "0.5 (3) Newton's Color Disk");
		addOption(document.order.Demo, "0.5 (4) Color Lights", "0.5 (4) Color Lights");
	}

	if(document.order.SubCat.value == "Holograms")									
	{
		addOption(document.order.Demo, "O.6 (1) Plane Hologram", "O.6 (1) Plane Hologram");
		addOption(document.order.Demo, "0.6 (2) Full View Hologram", "0.6 (2) Full View Hologram");
		addOption(document.order.Demo, "0.6 (3) \"Star Trek\" Reflection Hologram", "0.6 (3) \"Star Trek\" Reflection Hologram");
	}

	if(document.order.SubCat.value == "Solar Energy")								
	{
		addOption(document.order.Demo, "O.7 Solar Car", "O.7 Solar Car");
	}

	if(document.order.SubCat.value == "Atmospheric and Hydrostatic Pressure")		
	{
		addOption(document.order.Demo, "F.1(1) - Magdeburg Plates", "F.1(1) - Magdeburg Plates");
		addOption(document.order.Demo, "F.1(2) - Bubble Burster", "F.1(2) - Bubble Burster");
		addOption(document.order.Demo, "F.1(3) - Constant Level Tubes", "F.1(3) - Constant Level Tubes");
		addOption(document.order.Demo, "F.1(4) - Water Pumps", "F.1(4) - Water Pumps");
		addOption(document.order.Demo, "F.1(5) - Intermittent Siphon", "F.1(5) - Intermittent Siphon");
		addOption(document.order.Demo, "F.1(6) - Metal Can", "F.1(6) - Metal Can");
		addOption(document.order.Demo, "F.1(7) - Torricelli's Law", "F.1(7) - Torricelli's Law");
		addOption(document.order.Demo, "F.1(8) - Lung Demonstration Apparatus", "F.1(8) - Lung Demonstration Apparatus");
		addOption(document.order.Demo, "F.1(9) - Cloud Formation", "F.1(9) - Cloud Formation");
		addOption(document.order.Demo, "F.1(10) - Blood Pressure Meter", "F.1(10) - Blood Pressure Meter");
	}

	if(document.order.SubCat.value == "Pascal's Principle")							
	{
		addOption(document.order.Demo, "F.2(1) - Glass Pressure Syringe", "F.2(1) - Glass Pressure Syringe");
		addOption(document.order.Demo, "F.2(2) - Water Pressure", "F.2(2) - Water Pressure");
		addOption(document.order.Demo, "F.2(3) - Constant Level Tubes", "F.2(3) - Constant Level Tubes");
	}

	if(document.order.SubCat.value == "Archimede's Principle")						
	{
		addOption(document.order.Demo, "F.3 - Bucket and Plummet", "F.3 - Bucket and Plummet");
	}

	if(document.order.SubCat.value == "Buoyancy and Density")						
	{
		addOption(document.order.Demo, "F.4 - Buoyance and Density", "F.4 - Buoyance and Density");
	}

	if(document.order.SubCat.value == "Surface Tension")
	{
		addOption(document.order.Demo, "F.5(1) - Film of Soap", "F.5(1) - Film of Soap");
		addOption(document.order.Demo, "F.5(2) - Surface Tension Apparatus", "F.5(2) - Surface Tension Apparatus");
		addOption(document.order.Demo, "F.5(3) - Capillary Apparatus", "F.5(3) - Capillary Apparatus");
		addOption(document.order.Demo, "F.5(4) - Centripetal Force", "F.5(4) - Centripetal Force");
	}

	if(document.order.SubCat.value == "Non-Newtonian Fluids") 
	{
		addOption(document.order.Demo, "F.6 - Non-Newtonian Fluids", "F.6 - Non-Newtonian Fluids");
	}

	if(document.order.SubCat.value == "Bernoulli's Theorem") 
	{
		addOption(document.order.Demo, "F.7(1) - Venturi Tube", "F.7(1) - Venturi Tube");
		addOption(document.order.Demo, "F.7(2) - Suspended Ping-Pong Ball", "F.7(2) - Suspended Ping-Pong Ball");
		addOption(document.order.Demo, "F.7(3) - Nozzle and Two Sheets of Cardboard", "F.7(3) - Nozzle and Two Sheets of Cardboard");
		addOption(document.order.Demo, "F.7(4) - Ball in a Funnel", "F.7(4) - Ball in a Funnel");
		addOption(document.order.Demo, "F.7(5) - Wind Storm and House Roofs", "F.7(5) - Wind Storm and House Roofs");
		addOption(document.order.Demo, "F.7(6) - Perfume Bottle", "F.7(6) - Perfume Bottle");
	}

	if(document.order.SubCat.value == "Convection")
	{
		addOption(document.order.Demo, "F.8(1) - Convection of Liquids Apparatus", "F.8(1) - Convection of Liquids Apparatus");
		addOption(document.order.Demo, "F.8(2) - Convection of Gases Apparatus", "F.8(2) - Convection of Gases Apparatus");
	}

	if(document.order.SubCat.value == "Temprature Dependence on Water Density - Density Ball") 
	{
		addOption(document.order.Demo, "F.9 - Temperature Dependence on Water Density - Density Ball", "F.9 - Temperature Dependence on Water Density - Density Ball");
	}

	if(document.order.SubCat.value == "Heat Radiation, Absorption and Reflection")
	{
		addOption(document.order.Demo, "H.1(1) - Crooke's Radiometer", "H.1(1) - Crooke's Radiometer");
		addOption(document.order.Demo, "H.1(2) - Concave Mirrors", "H.1(2) - Concave Mirrors");
		addOption(document.order.Demo, "H.1(3) - Solar Furnace", "H.1(3) - Solar Furnace");
	}

	if(document.order.SubCat.value == "Thermal Expansion")
	{
		addOption(document.order.Demo, "H.2(1) - Ball and Ring Set", "H.2(1) - Ball and Ring Set");
		addOption(document.order.Demo, "H.2(2) - Unequal Expansion Bar", "H.2(2) - Unequal Expansion Bar");
		addOption(document.order.Demo, "H.2(3) - Rubber Band Motor", "H.2(3) - Rubber Band Motor");
	}

	if(document.order.SubCat.value == "Heat Conductivity")
	{
		addOption(document.order.Demo, "H.3 - Heat Conductivity", "H.3 - Heat Conductivity");
	}

	if(document.order.SubCat.value == "Specific Heat") 
	{
		addOption(document.order.Demo, "H.4 - Specific Heat", "H.4 - Specific Heat");
	}

	if(document.order.SubCat.value == "Lava Lite Lamp")
	{
		addOption(document.order.Demo, "H.5 - Lava Lite Lamp", "H.5 - Lava Lite Lamp");
	}

	if(document.order.SubCat.value == "Change of State")
	{
		addOption(document.order.Demo, "T.1(1) - Cryophorus", "T.1(1) - Cryophorus");
		addOption(document.order.Demo, "T.1(2) - Metal Can", "T.1(2) - Metal Can");
		addOption(document.order.Demo, "T.1(3) - Liquid Nitrogen Demonstration", "T.1(3) - Liquid Nitrogen Demonstration");
		addOption(document.order.Demo, "T.1(4) - PVT Models for CO2 and H2O", "T.1(4) - PVT Models for CO2 and H2O");
		addOption(document.order.Demo, "T.1(5) - Pulse Glass", "T.1(5) - Pulse Glass");
		addOption(document.order.Demo, "T.1(6) - Supercooled Demo", "T.1(6) - Supercooled Demo");
	}

	if(document.order.SubCat.value == "Mechanical Equivalent of Heat") 
	{
		addOption(document.order.Demo, "T.2(1) - Vapor Pressure", "T.2(1) - Vapor Pressure");
		addOption(document.order.Demo, "T.2(2) - Mechanical Equivalent of Heat Apparatus", "T.2(2) - Mechanical Equivalent of Heat Apparatus");
	}

	if(document.order.SubCat.value == "Thermal Behavior of Gases")
	{
		addOption(document.order.Demo, "T.3(1) - Shaving Cream Demonstration", "T.3(1) - Shaving Cream Demonstration");
		addOption(document.order.Demo, "T.3(2) - Compression Ignitor ", "T.3(2) - Compression Ignitor ");
	}

	if(document.order.SubCat.value == "Joule Thompson Model")
	{
		addOption(document.order.Demo, "T.4 - Joule Thompson Effect", "T.4 - Joule Thompson Effect");
	}

	if(document.order.SubCat.value == "Engine Models")
	{
		addOption(document.order.Demo, "T.5(1) - Drinking Bird", "T.5(1) - Drinking Bird");
		addOption(document.order.Demo, "T.5(2) - Hero's Jet Engine", "T.5(2) - Hero's Jet Engine");
		addOption(document.order.Demo, "T.5(3) - Steam Engine", "T.5(3) - Steam Engine");
		addOption(document.order.Demo, "T.5(4) - Stirling Cycle Hot-Air Engine", "T.5(4) - Stirling Cycle Hot-Air Engine");
		addOption(document.order.Demo, "T.5(5) - Two-Stroke Engine", "T.5(5) - Two-Stroke Engine");
		addOption(document.order.Demo, "T.5(6) - Four-Stroke Engine", "T.5(6) - Four-Stroke Engine");
		addOption(document.order.Demo, "T.5(7) - Thermoelectric Converter", "T.5(7) - Thermoelectric Converter");
	}

	if(document.order.SubCat.value == "Thermocouple")
	{
		addOption(document.order.Demo, "T.6(1) - Thermocouple", "T.6(1) - Thermocouple");
	}

	if(document.order.SubCat.value == "Attraction, Repulsion and Induction")
	{
		addOption(document.order.Demo, "E.1(1) Pith Balls", "E.1(1) Pith Balls");
		addOption(document.order.Demo, "E.1(2) Braun Electroscope", "E.1(2) Braun Electroscope");
		addOption(document.order.Demo, "E.1(3) Leaf Electroscope", "E.1(3) Leaf Electroscope");
		addOption(document.order.Demo, "E.1(4) Demonstration Electroscope", "E.1(4) Demonstration Electroscope");
		addOption(document.order.Demo, "E.1(5) Stream of Water", "E.1(5) Stream of Water");
		addOption(document.order.Demo, "E.1(6) Electrophorous", "E.1(6) Electrophorous");
		addOption(document.order.Demo, "E.1(7) Induction Spheres", "E.1(7) Induction Spheres");
	}

	if(document.order.SubCat.value == "Wimshurst Static Machine and Accessories")
	{
		addOption(document.order.Demo, "E.2(1) Wimshurst Static Generator", "E.2(1) Wimshurst Static Generator");
		addOption(document.order.Demo, "E.2(2) Bell Chimes", "E.2(2) Bell Chimes");
		addOption(document.order.Demo, "E.2(3) Electric Whirl", "E.2(3) Electric Whirl");
	}

	if(document.order.SubCat.value == "Van De Graaff Generator")
	{
		addOption(document.order.Demo, "E.3(1) Van de Graaff Generator with Discharger", "E.3(1) Van de Graaff Generator with Discharger");
		addOption(document.order.Demo, "E.3(2) Van de Graaff's Accessories", "E.3(2) Van de Graaff's Accessories");
	}

	if(document.order.SubCat.value == "Gauss Law") 
	{
		addOption(document.order.Demo, "E.5(1) Hollow Cylinder", "E.5(1) Hollow Cylinder");
		addOption(document.order.Demo, "E.5(2) Faraday Cage", "E.5(2) Faraday Cage");
		addOption(document.order.Demo, "E.5(3) Faraday Ice Pail Experiment", "E.5(3) Faraday Ice Pail Experiment");
	}

	if(document.order.SubCat.value == "Parallel State Capacitor") 
	{
		addOption(document.order.Demo, "C.1 - Parallel Plate Capacitor", "C.1 - Parallel Plate Capacitor");
	}

	if(document.order.SubCat.value == "Paper, electrolytic and Variable Capacitors")
	{
		addOption(document.order.Demo, "C.2 - Paper, Electrolytic and Variable Capacitors", "C.2 - Paper, Electrolytic and Variable Capacitors");
	}

	if(document.order.SubCat.value == "Dissectable Leyden Jar")
	{
		addOption(document.order.Demo, "C.3 - Dissectable Leyden Jar", "C.3 - Dissectable Leyden Jar");
	}

	if(document.order.SubCat.value == "Energy in a Capacitor") 
	{
		addOption(document.order.Demo, "C.4(1) - Driving a Motor", "C.4(1) - Driving a Motor");
		addOption(document.order.Demo, "C.4(2) - Discharging with a Metal Bar", "C.4(2) - Discharging with a Metal Bar");
		addOption(document.order.Demo, "C.4(3) - Wire Exploder", "C.4(3) - Wire Exploder");
	}

	if(document.order.SubCat.value == "RC Time Constant") 
	{
		addOption(document.order.Demo, "C.5 - Neon-Tube Relaxation Oscillator Circuit", "C.5 - Neon-Tube Relaxation Oscillator Circuit");
	}

	if(document.order.SubCat.value == "Lamp Board")
	{
		addOption(document.order.Demo, "EL.1 - Lamp Board", "EL.1 - Lamp Board");
	}

	if(document.order.SubCat.value == "Resistors in Series and Parallel")
	{
		addOption(document.order.Demo, "EL.2 - Resistors in Series and Parallel", "EL.2 - Resistors in Series and Parallel");
	}

	if(document.order.SubCat.value == "Piezoelectric Demonstrator") 
	{
		addOption(document.order.Demo, "EL.3 - Piezoelectric Demonstrator", "EL.3 - Piezoelectric Demonstrator");
	}

	if(document.order.SubCat.value == "Thermocouple")
	{
		addOption(document.order.Demo, "EL.4 - Thermocouple", "EL.4 - Thermocouple");
	}


	if(document.order.SubCat.value == "Solar Radiation and Electrical Current") 
	{
		addOption(document.order.Demo, "EL.5 - Solar Car", "EL.5 - Solar Car");
	}

	if(document.order.SubCat.value == "Conductivity of a Solution") 
	{
		addOption(document.order.Demo, "EL.6 - Conductivity of a Solution", "EL.6 - Conductivity of a Solution");
	}

	if(document.order.SubCat.value == "DC Measurements")
	{
		addOption(document.order.Demo, "EL.7 - DC Measurements", "EL.7 - DC Measurements");
	}

	if(document.order.SubCat.value == "Magnetic Field") 
	{
		addOption(document.order.Demo, "MG.1 - Magnetic Field", "MG.1 - Magnetic Field");
	}

	if(document.order.SubCat.value == "Floating Magnets")
	{
		addOption(document.order.Demo, "MG.2 - Floating Magnets", "MG.2 - Floating Magnets");
	}

	if(document.order.SubCat.value == "Magnetic Poles") 
	{
		addOption(document.order.Demo, "MG.3 - Magnetic Poles", "MG.3 - Magnetic Poles");
	}

	if(document.order.SubCat.value == "Magnetic Property of Iron") 
	{
		addOption(document.order.Demo, "MG.4 - Magnetic Property of Iron", "MG.4 - Magnetic Property of Iron");
	}

	if(document.order.SubCat.value == "Domains") 
	{
		addOption(document.order.Demo, "MG.5 Domains", "MG.5 Domains");
	}

	if(document.order.SubCat.value == "Magnetic Dip Needle")
	{
		addOption(document.order.Demo, "MG.6 Magnetic Dip Needle", "MG.6 Magnetic Dip Needle");
	}

	if(document.order.SubCat.value == "Magnetic Effects of Current") 
	{
		addOption(document.order.Demo, "EM.1(1) - Oersted's Law Apparatus", "EM.1(1) - Oersted's Law Apparatus");
		addOption(document.order.Demo, "EM.1(2) - Magnetic Field About a Wire - Compass Board", "EM.1(2) - Magnetic Field About a Wire - Compass Board");
		addOption(document.order.Demo, "EM.1(3) - Magnetic Field About Two Parallel Wires", "EM.1(3) - Magnetic Field About Two Parallel Wires");
	}

	if(document.order.SubCat.value == "Induced Current") 
	{
		addOption(document.order.Demo, "EM.2(1) Thermoelectric Pair", "EM.2(1) Thermoelectric Pair");
		addOption(document.order.Demo, "EM.2(2) Faraday Electromagnetic Induction Experiment", "EM.2(2) Faraday Electromagnetic Induction Experiment");
		addOption(document.order.Demo, "EM.2(3) Induction Rails", "EM.2(3) Induction Rails");
		addOption(document.order.Demo, "EM.2(4) Current Coupled Coils", "EM.2(4) Current Coupled Coils");
		addOption(document.order.Demo, "EM.2(5) Induced Current - Two Coils", "EM.2(5) Induced Current - Two Coils");
		addOption(document.order.Demo, "EM.2(6) Jumping Ring Experiment", "EM.2(6) Jumping Ring Experiment");
		addOption(document.order.Demo, "EM.2(7) The Submerged Lamp", "EM.2(7) The Submerged Lamp");
		addOption(document.order.Demo, "EM.2(8) Force Between a Coil and a Magnet", "EM.2(8) Force Between a Coil and a Magnet");
		addOption(document.order.Demo, "EM.2(9) Force Between Two Coils", "EM.2(9) Force Between Two Coils");
		addOption(document.order.Demo, "EM.2(10) Electromagnetic Damping", "EM.2(10) Electromagnetic Damping");
	}

	if(document.order.SubCat.value == "Transformers") 
	{
		addOption(document.order.Demo, "EM.3(1) - The Small Trasformer", "EM.3(1) - The Small Trasformer");
		addOption(document.order.Demo, "EM.3(2) - Induction Coil Transformer", "EM.3(2) - Induction Coil Transformer");
		addOption(document.order.Demo, "EM.3(3) - Tesla Coil", "EM.3(3) - Tesla Coil");
		addOption(document.order.Demo, "EM.3(4) - Mutal Induction of a Transformer", "EM.3(4) - Mutal Induction of a Transformer");
	}

	if(document.order.SubCat.value == "Force Between Parallel Current-Carrying Conductors")
	{
		addOption(document.order.Demo, "EM.4(1) Dancing Coil", "EM.4(1) Dancing Coil");
		addOption(document.order.Demo, "EM.4(2) Copper Strip", "EM.4(2) Copper Strip");
		addOption(document.order.Demo, "EM.4(3) Attracted Rings", "EM.4(3) Attracted Rings");
	}

	if(document.order.SubCat.value == "Eddy Current")
	{
		addOption(document.order.Demo, "EM.5(1) - Swinging Aluminum Plate", "EM.5(1) - Swinging Aluminum Plate");
		addOption(document.order.Demo, "EM.5(2) - Eddy Current Motor", "EM.5(2) - Eddy Current Motor");
		addOption(document.order.Demo, "EM.5(3) - Eddy Current Levitator", "EM.5(3) - Eddy Current Levitator");
		addOption(document.order.Demo, "EM.5(4) - Lenz's Law", "EM.5(4) - Lenz's Law");
	}

	if(document.order.SubCat.value == "Current in a Magnetic Field") 
	{
		addOption(document.order.Demo, "EM.6(1) - An Estimate by a Spring Balance", "EM.6(1) - An Estimate by a Spring Balance");
		addOption(document.order.Demo, "EM.6(2) - Faraday's Motor", "EM.6(2) - Faraday's Motor");
		addOption(document.order.Demo, "M.6(3) - Mechanical Effects on a Wire", "M.6(3) - Mechanical Effects on a Wire");
		addOption(document.order.Demo, "EM.6(4) - DC Electric Motor", "EM.6(4) - DC Electric Motor");
		addOption(document.order.Demo, "EM.6(5) - Conducting Rails", "EM.6(5) - Conducting Rails");
		addOption(document.order.Demo, "EM.6(6) - Light-Bulb - AC/DC Difference", "EM.6(6) - Light-Bulb - AC/DC Difference");
		addOption(document.order.Demo, "EM.6(7) - Electromagnetic Swing", "EM.6(7) - Electromagnetic Swing");
		addOption(document.order.Demo, "EM.6(8) - Electron Motion in a Uniform Magnetic Field", "EM.6(8) - Electron Motion in a Uniform Magnetic Field");
	}

	if(document.order.SubCat.value == "Electric Generator")
	{
		addOption(document.order.Demo, "EM.7 Electric Generator", "EM.7 Electric Generator");
	}

	if(document.order.SubCat.value == "Galvanometer")
	{
		addOption(document.order.Demo, "EM.8 - Galvanometer", "EM.8 - Galvanometer");
	}

	if(document.order.SubCat.value == "LRC Circuits") 
	{
		addOption(document.order.Demo, "EM.9(1) - Electric Light Dimmer - RL in Series", "EM.9(1) - Electric Light Dimmer - RL in Series");
		addOption(document.order.Demo, "EM.9(2) - LRC in Series	", "EM.9(2) - LRC in Series	");
		addOption(document.order.Demo, "EM.9(3) - Resonance Curve in LRC Circuits", "EM.9(3) - Resonance Curve in LRC Circuits");
		addOption(document.order.Demo, "EM.9(4) - Phase Difference in a RC Circuit", "EM.9(4) - Phase Difference in a RC Circuit");
	}

	if(document.order.SubCat.value == "Hertzian Waves")
	{
		addOption(document.order.Demo, "EM.10 - Short Wave Radio Demonstration Apparatus", "EM.10 - Short Wave Radio Demonstration Apparatus");
	}

	if(document.order.SubCat.value == "Resistance of Conductors")
	{
		addOption(document.order.Demo, "EM.11 - Resistance of Conductors - Temperature Dependence", "EM.11 - Resistance of Conductors - Temperature Dependence");
	}

	if(document.order.SubCat.value == "Cathode Ray Tubes")
	{
		addOption(document.order.Demo, "MP.1(1) Kinetic Energy Effect", "MP.1(1) Kinetic Energy Effect");
		addOption(document.order.Demo, "MP.1(2) Shadow Effect - The Maltese Cross", "MP.1(2) Shadow Effect - The Maltese Cross");
	}

	if(document.order.SubCat.value == "Electron Motion in a Uniform Magnetic Field")
	{
		addOption(document.order.Demo, "MP.2 Electron Motion in a Uniform Magnetic Field", "MP.2 Electron Motion in a Uniform Magnetic Field");
	}

	if(document.order.SubCat.value == "Crystal Structure")
	{
		addOption(document.order.Demo, "MP.3 Crystal Structure", "MP.3 Crystal Structure");
	}

	if(document.order.SubCat.value == "Electron Diffraction") 
	{
		addOption(document.order.Demo, "MP.4 Electron Diffraction", "MP.4 Electron Diffraction");
	}

	if(document.order.SubCat.value == "Radioactivity")
	{
		addOption(document.order.Demo, "MP.5(1) Geiger Counter", "MP.5(1) Geiger Counter");
		addOption(document.order.Demo, "MP.5(2) Diffusion Cloud Chamber", "MP.5(2) Diffusion Cloud Chamber");
	}

	if(document.order.SubCat.value == "Superconductivity")
	{
		addOption(document.order.Demo, "MP.6 Superconductivity", "MP.6 Superconductivity");
	}

	if(document.order.SubCat.value == "Fluorescent Liquids Set") 
	{
		addOption(document.order.Demo, "MP.7 Fluroscent Liquids Set", "MP.7 Fluroscent Liquids Set");
	}
}


function removeAllOptions(selectbox)
{
	var i;
	for(i=selectbox.options.length-1;i>=0;i--)
	{
		//selectbox.options.remove(i);
		selectbox.remove(i);
	}
}

function addOption(selectbox, value, text )
{
	var optn = document.createElement("OPTION");
	optn.text = text;
	optn.value = value;
	selectbox.options.add(optn);
}

function checkForm()
{
	if(document.order.Name.value == '')
	{
		alert('Please enter your Name');
		document.order.Name.focus();
		return false;
	}
	else if(document.order.EMail.value == '')
	{
		alert('Please enter your EMail address');
		document.order.EMail.focus();
		return false;
	}	
	else if(document.order.Category.value == 'Category')
	{
		alert('Please select a category');
		document.order.Category.focus();
		return false;
	}
	else if(document.order.SubCat.value == 'Sub Category')
	{
		alert('Please select a sub-category');
		document.order.Demo.focus();
		return false;
	}
	else if(document.order.Demo.value == 'Demonstration')
	{
		alert('Please select a demonstration');
		document.order.Demo.focus();
		return false;
	}
}