Variable Scope Sorunu (ActionScript 3.0)

var xmlData:XML; 
  var xmlLoader:URLLoader = new URLLoader(); 
  var xmlRequest:URLRequest = new URLRequest("data.xml"); 
  xmlLoader.load(xmlRequest); 
  xmlLoader.addEventListener(Event.COMPLETE, onComplete); 
   
  function onComplete(event:Event):void 
  { 
      var loader:URLLoader = event.target as URLLoader; 
      if (loader != null) 
      { 
          xmlData = new XML(loader.data); 
          trace(xmlData.toXMLString()); 
      } 
      else 
      { 
          trace("loader is not a URLLoader!"); 
      } 
  } 
   
  trace(xmlData == null);