function enable_disable_shipping(frm_element, checkbox_element_id){
	
	var frm_element			= document.getElementById(frm_element);
	var checkbox_element	= document.getElementById(checkbox_element_id);
	
	if(checkbox_element.checked){
		var disable_elements	=  true;
	}
	else{
		var disable_elements	=  false;
	}
	
	for(var n = 0; n < frm_element.elements.length; n++){
		var element_name	= frm_element.elements[n].name.toUpperCase();
		if(element_name.indexOf("F_SHIPPING") != -1){
			frm_element.elements[n].value		= "";
			frm_element.elements[n].disabled	= disable_elements;
		}
	}
	
}

function disable_submit(element_id){
	if(!document.getElementById)	return;
	var element_ref	= document.getElementById(element_id);
	if(element_ref){
		element_ref.disabled = true;
	}
}