Return value from addEventListener

[FONT=Tahoma][SIZE=5]Where do you retrieve return values where the function is called from an eventListener?[/SIZE][/FONT]

Hello Kirupians! :love:
Anyways, I have this code:

var output:String = "";
    function loadFrom(url:String):String {
        var urll:URLLoader = new URLLoader();
        urll.addEventListener(Event.COMPLETE, completeHandler);
        urll.load(new URLRequest(url));
    function completeHandler(event:Event):void {
        output = as String;
        return output;

completeHandler() is called when the URLLoader is finished loading.
then completeHandler() returns a value, but where or how do I access that?

Thank you.