Fading In and resizing images from an .XML!

I have created an XML based photo gallery. Its split into two parts, the thumnail holder and the main image holder. When you click a thumbnail, the image loads fine. However I would like the image to automatically resize when a thumbnail is clicked, and for the image to fade in, not just appear!
Any idea anyone? They would be much appreciated!!

Here is my action script code so far >

myPhoto = new XML();
myPhoto.ignoreWhite = true;
myPhoto.onLoad = function(success) {
numimages = this.firstChild.childNodes.length;
spacing = 70;
for (i=0; i<numimages; i++) {
picHolder = this.firstChild.childNodes*;
thumbHolder = thumbnails.createEmptyMovieClip("thumbnail"+i, i);
thumbHolder._x = i*spacing;
thumbHolder.title = picHolder.attributes.title;
thumbHolder.main = picHolder.attributes.main;
thumbLoader = thumbHolder.createEmptyMovieClip("thumbnail_image"+i, i);
thumbHolder.onRelease = function() {