[bav]

Давайте разберемся, что вам непонятно из кода в примере?

package {
    import flash.display.Loader;
    import flash.display.Sprite;
    import flash.events.*;
    import flash.net.URLRequest;
 
    public class LoaderExample extends Sprite {
        private var url:String = "Image.gif";
 
        public function LoaderExample() {
            var loader:Loader = new Loader();
            configureListeners(loader.contentLoaderInfo);
            loader.addEventListener(MouseEvent.CLICK, clickHandler);
 
            var request:URLRequest = new URLRequest(url);
            loader.load(request);
 
            addChild(loader);
        }
 
        private function configureListeners(dispatcher:IEventDispatcher):void {
            dispatcher.addEventListener(Event.COMPLETE, completeHandler);
            dispatcher.addEventListener(HTTPStatusEvent.HTTP_STATUS, httpStatusHandler);
            dispatcher.addEventListener(Event.INIT, initHandler);
            dispatcher.addEventListener(IOErrorEvent.IO_ERROR, ioErrorHandler);
            dispatcher.addEventListener(Event.OPEN, openHandler);
            dispatcher.addEventListener(ProgressEvent.PROGRESS, progressHandler);
            dispatcher.addEventListener(Event.UNLOAD, unLoadHandler);
        }
 
        private function completeHandler(event:Event):void {
            trace("completeHandler: " + event);
        }
 
        private function httpStatusHandler(event:HTTPStatusEvent):void {
            trace("httpStatusHandler: " + event);
        }
 
        private function initHandler(event:Event):void {
            trace("initHandler: " + event);
        }
 
        private function ioErrorHandler(event:IOErrorEvent):void {
            trace("ioErrorHandler: " + event);
        }
 
        private function openHandler(event:Event):void {
            trace("openHandler: " + event);
        }
 
        private function progressHandler(event:ProgressEvent):void {
            trace("progressHandler: bytesLoaded=" + event.bytesLoaded + " bytesTotal=" + event.bytesTotal);
        }
 
        private function unLoadHandler(event:Event):void {
            trace("unLoadHandler: " + event);
        }
 
        private function clickHandler(event:MouseEvent):void {
            trace("clickHandler: " + event);
            var loader:Loader = Loader(event.target);
            loader.unload();
        }
    }
}

Добавлено через 10 минут
Упростим.

package {
 
    import flash.display.Sprite;
    import flash.display.Loader;
    import flash.events.Event;
    import flash.net.URLRequest;
 
    public class Main extends Sprite
    {
        private var loader:Loader;
 
        public function Main ()
        {
            if (stage) init();
            else addEventListener(Event.ADDED_TO_STAGE, init);
        }
        private function init(e:Event = null):void
        {
            removeEventListener(Event.ADDED_TO_STAGE, init);
            loader = new Loader();
            loader.contentLoaderInfo.addEventListener(Event.COMPLETE, completeHandler);
            addChild(loader);
 
            loader.load(new URLRequest("image.jpg"));
        }
 
        private function completeHandler(e:Event):void
        {
            trace("Complete");
        }
    }