var fileToLoad:String = "myFile.swf"; var req:URLRequest = new URLRequest(fileToLoad);
var loader:Loader = new Loader();

     loader.contentLoaderInfo.addEventListener(ProgressEvent.PROGRESS,
        fileLoading);
     loader.contentLoaderInfo.addEventListener(Event.COMPLETE, fileLoaded);
     loader.load(req);


function fileLoading(event:ProgressEvent):void
{
     var percent:Number = event.bytesLoaded/event.bytesTotal;
     var roundedPercent:uint = Math.ceil(percent * 100);
     bwRX_mc.gotoAndStop(roundedPercent);
                                                                          }

bwRX_mc.stop();


function fileLoaded(event:Event):void
{
     removeChild(bwRX_mc);
     addChild(loader);
}