MovieClipLoader loadClip fails how can I load a defualt MC

Hi I'm using the MovieClipLoader class to load pictures and set them on stage but what if the loadClip fails file not found how can I load a default movieclip see code example:
function thumbnails_fn(k) {
thumbnail_mc.createEmptyMovieClip("t"+k, thumbnail_mc.getNextHighestDepth());
tlistener = new Object();
tlistener.onLoadInit = function(target_mc) {
target_mc._x = hit_left._x+(target_mc._width)*k;
target_mc.pictureValue = k;
target_mc.onRelease = function() {
p = this.pictureValue-1;
nextImage();
};
target_mc.onRollOver = function() {
this._alpha = 50;
thumbNailScroller();
};
target_mc.onRollOut = function() {
this._alpha = 100;
};
};

image_mcl = new MovieClipLoader();
image_mcl.addListener(tlistener);
//now load the url and it fails...
image_mcl.loadClip(thumbnails[k], "thumbnail_mc.t"+k);
tlistener.onLoadError = function(target_mc, errormsg) {
target_mc.loadMovie("thumbMC.swf");
};
the swf is load but I cant see it on the stage see the list object that the swf is set on the movieclip:
Movie Clip: Frame=1 Target="_level0.thumbnail_mc"
Movie Clip: Frame=1 Target="_level0.thumbnail_mc.t1"
Movie Clip: Frame=1 Target="_level0.thumbnail_mc.t1.instance13"
Shape:
Edit Text: Target="_level0.thumbnail_mc.t1.instance13.m_text" Variable= Visible=true Text = אבדהחטכל.."

what is wrong here I missing somthing!!