function fillCategory(){ 
 // this function is used to fill the category list on load
    addOption(document.drop_list.make, "Chevrolet", "Chevrolet", "");
    addOption(document.drop_list.make, "Citroen", "Citroen", "");
    addOption(document.drop_list.make, "Daf", "Daf", "");
    addOption(document.drop_list.make, "Daihatsu", "Daihatsu", "");
    addOption(document.drop_list.make, "Fiat", "Fiat", "");
    addOption(document.drop_list.make, "Ford", "Ford", "");
    addOption(document.drop_list.make, "Hyundai", "Hyundai", "");
    addOption(document.drop_list.make, "Isuzu", "Isuzu", "");
    addOption(document.drop_list.make, "Iveco", "Iveco", "");
    addOption(document.drop_list.make, "Kia", "Kia", "");
    addOption(document.drop_list.make, "Land Rover", "Land Rover", "");
    addOption(document.drop_list.make, "LDV", "LDV", "");
    addOption(document.drop_list.make, "Mazda", "Mazda", "");
    addOption(document.drop_list.make, "Mercedes", "Mercedes", "");
    addOption(document.drop_list.make, "Mitsubishi", "Mitsubishi", "");
    addOption(document.drop_list.make, "Nissan", "Nissan", "");
    addOption(document.drop_list.make, "Peugeot", "Peugeot", "");
    addOption(document.drop_list.make, "Proton", "Proton", "");
    addOption(document.drop_list.make, "Renault", "Renault", "");
    addOption(document.drop_list.make, "Seat", "Seat", "");
    addOption(document.drop_list.make, "Ssangyoung", "Ssangyoung", "");
    addOption(document.drop_list.make, "Suzuki", "Suzuki", "");
    addOption(document.drop_list.make, "Toyota", "Toyota", "");
    addOption(document.drop_list.make, "Vauxhall", "Vauxhall", "");
    addOption(document.drop_list.make, "Volkswagen", "Volkswagen", "");
}

function SelectSubCat(){
// ON selection of category this function will work

removeAllOptions(document.drop_list.model);
addOption(document.drop_list.model, "", "All", "");

if (document.drop_list.make.value == 'Chevrolet') {
    addOption(document.drop_list.model, "Camaro", "Camaro");
    addOption(document.drop_list.model, "Colorado", "Colorado");
}
if (document.drop_list.make.value == 'Citroen') {
    addOption(document.drop_list.model, "Berlingo", "Berlingo");
    addOption(document.drop_list.model, "Berlingo Multispace", "Berlingo Multispace");
    addOption(document.drop_list.model, "Dispatch", "Dispatch", "");
    addOption(document.drop_list.model, "Nemo", "Nemo", "");
    addOption(document.drop_list.model, "Relay", "Relay", "");
}
if (document.drop_list.make.value == 'Daf') {
    addOption(document.drop_list.model, "45", "45");
    addOption(document.drop_list.model, "CF Series", "CF Series");
    addOption(document.drop_list.model, "LF Series", "LF Series");
    addOption(document.drop_list.model, "XF Series", "XF Series");
}
if (document.drop_list.make.value == 'Daihatsu') {
    addOption(document.drop_list.model, "Hi-Jet", "Hi-Jet");
    addOption(document.drop_list.model, "Extol", "Extol");
}
if (document.drop_list.make.value == 'Dodge') {
    addOption(document.drop_list.model, "Ram", "Ram");
}
if (document.drop_list.make.value == 'Fiat') {
    addOption(document.drop_list.model, "Doblo", "Doblo");
    addOption(document.drop_list.model, "Ducato", "Ducato");
    addOption(document.drop_list.model, "Fiorino", "Fiorino");
    addOption(document.drop_list.model, "Punto", "Punto");
    addOption(document.drop_list.model, "Scudo", "Scudo");
}
if (document.drop_list.make.value == 'Ford') {
    addOption(document.drop_list.model, "Cargo", "Cargo");
    addOption(document.drop_list.model, "Courier", "Courier");
    addOption(document.drop_list.model, "F-Series", "F-Series");
    addOption(document.drop_list.model, "Transit", "Transit");
    addOption(document.drop_list.model, "Transit Connect", "Transit Connect");
}
if (document.drop_list.make.value == 'Hyundai') {
    addOption(document.drop_list.model, "H100", "H100");
    addOption(document.drop_list.model, "iLoad", "iLoad");
    addOption(document.drop_list.model, "Santa Fe", "Santa Fe");
    addOption(document.drop_list.model, "Terrecan", "Terrecan");
}
if (document.drop_list.make.value == 'Isuzu') {
    addOption(document.drop_list.model, "N-Series", "N-Series");
    addOption(document.drop_list.model, "Rodeo", "Rodeo");
    addOption(document.drop_list.model, "Trooper", "Trooper");
}
if (document.drop_list.make.value == 'Iveco') {
    addOption(document.drop_list.model, "75E15", "75E15");
    addOption(document.drop_list.model, "Daily", "Daily");
    addOption(document.drop_list.model, "Eurocargo", "Eurocargo");
}
if (document.drop_list.make.value == 'Land Rover') {
    addOption(document.drop_list.model, "Defender", "Defender");
    addOption(document.drop_list.model, "Freelander", "Freelander");
    addOption(document.drop_list.model, "Range Rover", "Range Rover");
    addOption(document.drop_list.model, "Range Rover Sport", "Range Rover Sport");
} 
if (document.drop_list.make.value == 'LDV') {
addOption(document.drop_list.model, "Convoy", "Convoy");
addOption(document.drop_list.model, "Maxus", "Maxus");
addOption(document.drop_list.model, "Pilot", "Pilot");
}
if (document.drop_list.make.value == 'Mazda') {
    addOption(document.drop_list.model, "B-Series", "B-Series");
    addOption(document.drop_list.model, "BT-50", "BT-50");
}
if (document.drop_list.make.value == 'Mercedes') {
    addOption(document.drop_list.model, "Atego", "Atego");
    addOption(document.drop_list.model, "Sprinter", "Sprinter");
    addOption(document.drop_list.model, "Vito", "Vito");
}
if (document.drop_list.make.value == 'Mitsubishi') {
    addOption(document.drop_list.model, "Canter", "Canter");
    addOption(document.drop_list.model, "L200", "L200");
    addOption(document.drop_list.model, "L300", "L300");
    addOption(document.drop_list.model, "Pajero", "Pajero");
    addOption(document.drop_list.model, "Shogun", "Shogun");
}
if (document.drop_list.make.value == 'Nissan') {
    addOption(document.drop_list.model, "Almera", "Almera");
    addOption(document.drop_list.model, "Cabstar", "Cabstar");
    addOption(document.drop_list.model, "Kubistar", "Kubistar");
    addOption(document.drop_list.model, "Navara", "Navara");
    addOption(document.drop_list.model, "Primastar", "Primastar");
    addOption(document.drop_list.model, "Vanette", "Vanette");
}
if (document.drop_list.make.value == 'Peugeot') {
    addOption(document.drop_list.model, "Boxer", "Boxer");
    addOption(document.drop_list.model, "Expert", "Expert");
    addOption(document.drop_list.model, "Partner", "Partner");
    addOption(document.drop_list.model, "Partner Combi", "Partner Combi");
}
if (document.drop_list.make.value == 'Proton') {
    addOption(document.drop_list.model, "Jumbuck", "Jumbuck");
}
if (document.drop_list.make.value == 'Renault') {
    addOption(document.drop_list.model, "Kangoo", "Kangoo");
    addOption(document.drop_list.model, "Magnum", "Magnum");
    addOption(document.drop_list.model, "Master", "Master");
    addOption(document.drop_list.model, "Midlum", "Midlum");
    addOption(document.drop_list.model, "Premium", "Premium");
    addOption(document.drop_list.model, "Trafic", "Trafic");
}
if (document.drop_list.make.value == 'Seat') {
    addOption(document.drop_list.model, "Inca", "Inca");
}
if (document.drop_list.make.value == 'Ssangyoung') {
    addOption(document.drop_list.model, "Rexton", "Rexton");
    addOption(document.drop_list.model, "Rexton II", "Rexton II");
}
if (document.drop_list.make.value == 'Suzuki') {
    addOption(document.drop_list.model, "Carry", "Carry");
}
if (document.drop_list.make.value == 'Toyota') {
    addOption(document.drop_list.model, "Corolla", "Corolla");
    addOption(document.drop_list.model, "Dyna", "Dyna");
    addOption(document.drop_list.model, "Hiace", "Hiace");
    addOption(document.drop_list.model, "Hilux", "Hilux");
    addOption(document.drop_list.model, "Landcruiser", "Landcruiser");
}
if (document.drop_list.make.value == 'Vauxhall') {
    addOption(document.drop_list.model, "Astravan", "Astravan");
    addOption(document.drop_list.model, "Brava", "Brava");
    addOption(document.drop_list.model, "Combo", "Combo");
    addOption(document.drop_list.model, "Corsa", "Corsa");
    addOption(document.drop_list.model, "Movano", "Movano");
    addOption(document.drop_list.model, "Vivaro", "Vivaro");
}
if (document.drop_list.make.value == 'Volkswagen') {
    addOption(document.drop_list.model, "Caddy", "Caddy");
    addOption(document.drop_list.model, "Crafter", "Crafter");
    addOption(document.drop_list.model, "LT", "LT");
    addOption(document.drop_list.model, "Transporter", "Transporter");
}

}
////////////////// 

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);
}