MovieClipLoader onLoadComplete problem

am dynamically creating a 2 movie clips in a class. in one movie clip i am loading the image using MovieClipLoader. everything is working fine. but the onLoadComplete method is not working properly.
i am using onLoadComplete method to find the width of the image but in onLoadComplete event the exact width is not calculating

code is here
__imageClip = createEmptyMovieClip(“MyImage”, this.getNextHighestDepth());

__canvasClip = createEmptyMovieClip("MyCanvas", this.getNextHighestDepth());

    imageLoader = new MovieClipLoader();
	mclListner.onLoadComplete = function():Void  {
		__fileWidth = _root.myLoader.__imageClip._width;
		__fileHeight = _root.myLoader.__imageClip._height;
	imageLoader.loadClip(__fileName, this.__imageClip);