ActionScript 3.0 :: Accessing Dynamically Created Movie Clips?

I'm trying to build a relatively simple photo gallery where the images are loaded via XML into thumbnail movieclips that have been dynamically generated, positioned and added to the display stack. I used a simple for loop to generate the thumbs and traced the thumb.name to make sure they all had unique instance names. I then added a listener to the thumb mcs in the for loop and created a function that traces the instance name of each thumb mc, to see if all is working, however, every thumb mc traces the same instance name. My question is how can I create the thumbs dynamically in a loop and, essentially, make them buttons that would display the big the full size photo.

Here is my prototype code:

ActionScript Code:
for (var i=0; i<12; i++) {
var thumb_mc:MovieClip = new thumb();
// Positioning: The xy coordinates are in an array outside the for loop.

[Code]......