function addEvent( obj, type, fn ){  // the add event function
    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] );
    }
}