How to dynamically give MC an instance names?

Now I have this code which is loading all the images from the xml file into a container and I need to set some ID to track which image should be opened bigger in another MC.
And I also need to use this ID to when user hovers mouse over an image it scales up a little using tweener.

private function loadThumbs():void
	for(var j:uint = 0; j < thumbs.length ;j++)
		MC = new MovieClip(); = "number " + j;	
		MC.x = j * thumbsSize;
		imgLoader = new Loader();
		imgLoader.load(new URLRequest(thumbs[j]));	
		MC.addEventListener(MouseEvent.CLICK, onClick);
		MC.addEventListener(MouseEvent.MOUSE_OVER, onMouseOver);
		MC.addEventListener(MouseEvent.MOUSE_OUT, onMouseOut);

When I trace at onClick event it shows the instance name.

How should I do?