ActionScript 2.0 :: Dynamic Thumbnails From XML?

I am building a dynamic thumbnail gallery, where each image links to a fullsize version. (Sounds simple so far, but wait!) The thumbnails are created dynamically - an xml document provides the image path and description. I create a movie clip for each one on the fly, then load the appropriate image into it.

My problem is when I try to convert each movieclip into a button which loads the fullsize image. Each button loads the same image- the last one in my xml document. If I try placing "img[i]" inside the onRelease function, it comes up undefined. Here's that bit of code:

var thisimage=img[i];
eval("thumbnail"+i).onRelease = function()
{
// do something
loadMovie (thisimage,_parent.emptyclip);
}

And here is all the actionscript:

var xpos=0;
function loadXML(loaded) {
if (loaded) {

[code]...