function addEvent(obj, type, fn){
  if (obj.addEventListener)
    obj.addEventListener(type, fn, false);
  else if (obj.attachEvent){
    obj["e"+type+fn] = fn;
    obj[type+fn] = function(){obj["e"+type+fn](window.event);}
    obj.attachEvent("on"+type, obj[type+fn]);
  }
}