// JavaScript Document
function replace_css(id,url){
  if(!document.getElementById) return false;
  var element = document.getElementById(id);
  if(!element || !element.cloneNode) return false;
  var new_node = element.cloneNode(true);
  new_node.href = url;
  element.parentNode.replaceChild(new_node,element);
  return true;
}