function fillCategory(){ 
 // this function is used to fill the category list on load
addOption(document.drop_list.Category, "MRI", "MRI", "");
addOption(document.drop_list.Category, "CT", "CT", "");
}

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

removeAllOptions(document.drop_list.SubCat);
removeAllOptions(document.drop_list.SubSubCat);
addOption(document.drop_list.SubCat, "", "--Select Your OEM--", "");
addOption(document.drop_list.SubSubCat, "", "--Select Your System--", "");

if(document.drop_list.Category.value == 'MRI'){
addOption(document.drop_list.SubCat,"SeimensMRI", "Seimens");
addOption(document.drop_list.SubCat,"GEMRI", "GE");
addOption(document.drop_list.SubCat,"HitachiMRI", "Hitachi");
addOption(document.drop_list.SubCat,"PickerMRI", "Picker");
addOption(document.drop_list.SubCat,"PhilipsMRI", "Philips");
addOption(document.drop_list.SubCat,"ToshibaMRI", "Toshiba");
}
if(document.drop_list.Category.value == 'CT'){
addOption(document.drop_list.SubCat,"SeimensCT", "Seimens");
addOption(document.drop_list.SubCat,"GECT", "GE");
addOption(document.drop_list.SubCat,"HitachiCT", "Hitachi");
addOption(document.drop_list.SubCat,"PickerCT", "Picker");
addOption(document.drop_list.SubCat,"PhilipsCT", "Philips");
addOption(document.drop_list.SubCat,"ToshibaCT", "Toshiba");
}

}


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

removeAllOptions(document.drop_list.SubSubCat);
addOption(document.drop_list.SubSubCat, "", "--Select Your System--", "");

if(document.drop_list.SubCat.value == 'SeimensMRI'){
addOption(document.drop_list.SubSubCat,"SeimensMRI", "Symphony 1.5T");
addOption(document.drop_list.SubSubCat,"SeimensMRI", "Harmony 1.0T");
addOption(document.drop_list.SubSubCat,"SeimensMRI", "Impact Expert 1.0T");
addOption(document.drop_list.SubSubCat,"SeimensMRI", "Vision 1.5T");
addOption(document.drop_list.SubSubCat,"SeimensMRI", "Open Viva");
addOption(document.drop_list.SubSubCat,"SeimensMRI", "Concerto");
addOption(document.drop_list.SubSubCat,"SeimensMRI", "Rhapsody");
}
if(document.drop_list.SubCat.value == 'SeimensCT'){
addOption(document.drop_list.SubSubCat,"SeimensCT", "Somatom AR Star");
addOption(document.drop_list.SubSubCat,"SeimensCT", "Somatom Plus 4 Power");
addOption(document.drop_list.SubSubCat,"SeimensCT", "Somatom Plus 4 Expert");
addOption(document.drop_list.SubSubCat,"SeimensCT", "Somatom Volume Zoom");
addOption(document.drop_list.SubSubCat,"SeimensCT", "Somatom Emotion");
addOption(document.drop_list.SubSubCat,"SeimensCT", "Somatom Sensation");
}
if(document.drop_list.SubCat.value == 'GEMRI'){
addOption(document.drop_list.SubSubCat,"GEMRI", "Singa LX K4 1.5T");
addOption(document.drop_list.SubSubCat,"GEMRI", "Signa Horizon 1.5T");
}
if(document.drop_list.SubCat.value == 'GECT'){
addOption(document.drop_list.SubSubCat,"GECT", "ProSpeed Single Slice");
addOption(document.drop_list.SubSubCat,"GECT", "CTi-Single Slice");
addOption(document.drop_list.SubSubCat,"GECT", "Lightspeed QXI/P");
addOption(document.drop_list.SubSubCat,"GECT", "FX/I Single Slice");
addOption(document.drop_list.SubSubCat,"GECT", "HiSpeed DX/I");
}
if(document.drop_list.SubCat.value == 'HitachiMRI'){
addOption(document.drop_list.SubSubCat,"HitachiMRI", "Aries I");
addOption(document.drop_list.SubSubCat,"HitachiMRI", "Aries II");
}
if(document.drop_list.SubCat.value == 'HitachiCT'){
addOption(document.drop_list.SubSubCat,"HitachiCT", "");
addOption(document.drop_list.SubSubCat,"HitachiCT", "");
}
if(document.drop_list.SubCat.value == 'PickerMRI'){
addOption(document.drop_list.SubSubCat,"PickerMRI", "Outlook Gold Proform");
addOption(document.drop_list.SubSubCat,"PickerMRI", "Polaris 1.0T");
addOption(document.drop_list.SubSubCat,"PickerMRI", "Eclispe 1.5T");
}
if(document.drop_list.SubCat.value == 'PickerCT'){
addOption(document.drop_list.SubSubCat,"PickerCT", "PQ5000");
}
if(document.drop_list.SubCat.value == 'PhilipsMRI'){
addOption(document.drop_list.SubSubCat,"PhilipsMRI", "Intera 1.5T");
addOption(document.drop_list.SubSubCat,"PhilipsMRI", "ACS NT 1.5T");
}
if(document.drop_list.SubCat.value == 'PhilipsCT'){
addOption(document.drop_list.SubSubCat,"PhilipsCT", "MX8000");
addOption(document.drop_list.SubSubCat,"PhilipsCT", "Brillance");
}
if(document.drop_list.SubCat.value == 'ToshibaMRI'){
addOption(document.drop_list.SubSubCat,"ToshibaMRI", "Opart .35T");
}
if(document.drop_list.SubCat.value == 'ToshibaCT'){
addOption(document.drop_list.SubSubCat,"ToshibaCT", "Asteion");
addOption(document.drop_list.SubSubCat,"ToshibaCT", "Aquillion");
}

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

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);
}