function fillCategory(){ 
 // this function is used to fill the category list on load
addOption(document.drop_list.OutputControl, "H", "     Tri-State (Disabled Output: High Impedance)", "");
addOption(document.drop_list.OutputControl, "J", "     Power Down (Disabled Output: Logic Low)", "");
addOption(document.drop_list.OutputControl, "K", "     Spread Disable (Spread Spectrum Output:Disabled)", "");
}

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

removeAllOptions(document.drop_list.SpreadSpec);
addOption(document.drop_list.SpreadSpec, "", "- Select Spread Spectrum Option -", "");

if(document.drop_list.OutputControl.value == 'H'){
addOption(document.drop_list.SpreadSpec,"A", "±0.25% Center Spread");
addOption(document.drop_list.SpreadSpec,"B", "±0.50% Center Spread");
addOption(document.drop_list.SpreadSpec,"C", "±1.00% Center Spread");
addOption(document.drop_list.SpreadSpec,"D", "-0.50% Down Spread");
addOption(document.drop_list.SpreadSpec,"E", "-1.00% Down Spread");
addOption(document.drop_list.SpreadSpec,"F", "-2.00% Down Spread");
}
if(document.drop_list.OutputControl.value == 'J'){
addOption(document.drop_list.SpreadSpec,"A", "±0.25% Center Spread");
addOption(document.drop_list.SpreadSpec,"B", "±0.50% Center Spread");
addOption(document.drop_list.SpreadSpec,"C", "±1.00% Center Spread");
addOption(document.drop_list.SpreadSpec,"D", "-0.50% Down Spread");
addOption(document.drop_list.SpreadSpec,"E", "-1.00% Down Spread");
addOption(document.drop_list.SpreadSpec,"F", "-2.00% Down Spread");
}
if(document.drop_list.OutputControl.value == 'K'){
addOption(document.drop_list.SpreadSpec,"D", "-0.50% Down Spread");
addOption(document.drop_list.SpreadSpec,"E", "-1.00% Down Spread");
addOption(document.drop_list.SpreadSpec,"F", "-2.00% Down Spread");
}

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

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);
}