function fillCategory(){ 
 // this function is used to fill the category list on load

   addOption(document.product_form.producent, "3", ".", "");
   addOption(document.product_form.producent, "1", "LENIAR", "");
   addOption(document.product_form.producent, "5", "OLFA", "");
   addOption(document.product_form.producent, "2", "STANDARDGRAPH", "");
   addOption(document.product_form.producent, "4", "WEDO", "");}

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

removeAllOptions(document.product_form.seria);


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

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);
}