Event Flex


                layout="absolute"
                initialize="initializeHandler(event)">
  
    
      private function initializeHandler(event:Event):void {
        var loader:URLLoader = new URLLoader(  );
        loader.load(new URLRequest("a.xml"));
        loader.addEventListener(SecurityErrorEvent.SECURITY_ERROR,securityErrorHandler);
      }
      private function securityErrorHandler(event:SecurityErrorEvent):void {
        errors.text += event + "\n";
      }