var datarray = new Array();

function nav()
   {
   var w = document.drop_list.manufacturerlist.selectedIndex;
   var url_add = document.drop_list.manufacturerlist.options[w].value;
   window.location.href = url_add;
   }

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

function doOptions(selectbox,datarray){
	for (keyVar in datarray){
	addOption(selectbox, keyVar, datarray[keyVar]);
	}
}