/******************************************
	hidden all select field 
*******************************************/
function hidden_selectfield(vform) {	
	if(document.forms[vform])	{	
		for(i=0; i<document.forms[vform].elements.length; i++) {	
			if(document.forms[vform].elements[i].type == "select-one")
				document.forms[vform].elements[i].style.visibility="hidden";	
		
		}
	}
}
/******************************************
	show all select field
*******************************************/
function show_selectfield(vform) {		
	if(document.forms[vform]) {	
		for(i=0; i<document.forms[vform].elements.length; i++) {	
			if(document.forms[vform].elements[i].type == "select-one")
				document.forms[vform].elements[i].style.visibility="visible";
		}
	}
}