ActionScript 3.0 :: How To Target Externally Loaded Objects

i have creating an image gallery of sorts. I have loaded my thumbnails through an xml like so:

Code:

function loadThumbs(){
for (var i = 0; i < totalElements; i++){
var thumb_url = elements[i].@thumbSrc;
trace("totalElements: " + totalElements);

[code]....

now i want to have it so that when u click a thumb, it re-layers them. I am able to get the one u click to the front of the order, but how can i tell the others to layer as i want? I guess the problem is that I cannot use the name of the display object and i can't user image_loader to setChildIndex with.

Code:

function replaceElementAndMoveThumb(event:MouseEvent):void{
setChildIndex(event.currentTarget, numChildren - 1);
trace(event.currentTarget);
}

I am thinking that in AS2 I would use the movieclip instance name, but don't think this works in AS3.