Modifying Thumbnail photo gallery tutorial

The following code is copied out of the Kirupa tutorial for the photogallery with thumbnails.

The problem that I am having is that I want to be able to thumnbnails with different widths. Heights are all the same but the widths are different because of the different aspect ratios.

I can’t seem to figure out a way to space each thumbnail evenly.

The way that it is done in the tutorial code below, it assumes that the thumbnails are all the same width so it just has to do multiplication on width of the current thumbnail it is placing.

The placement of the thumbnails is the function at the bottom (thumbnails_fn). Please help.

function loadXML(loaded) {
if (loaded) {
xmlNode = this.firstChild;
image = [];
description = [];
thumbnails = [];
total = xmlNode.childNodes.length;
for (i=0; i<total; i++) {
image* = xmlNode.childNodes*.childNodes[0].firstChild.nodeValue;
description* = xmlNode.childNodes*.childNodes[1].firstChild.nodeValue;
thumbnails* = xmlNode.childNodes*.childNodes[2].firstChild.nodeValue;
thumbnails_fn(i);
}
firstImage();
} else {
content = "file not loaded!";
}
}
xmlData = new XML();
xmlData.ignoreWhite = true;
xmlData.onLoad = loadXML;
xmlData.load("images.xml");
///////////////////////////////////// 
listen = new Object();
listen.onKeyDown = function() {
if (Key.getCode() == Key.LEFT) {
prevImage();
} else if (Key.getCode() == Key.RIGHT) {
nextImage();
}
};
Key.addListener(listen);
previous_btn.onRelease = function() {
prevImage();
};
next_btn.onRelease = function() {
nextImage();
};
///////////////////////////////////// 
p = 0;
this.onEnterFrame = function() {
filesize = picture.getBytesTotal();
loaded = picture.getBytesLoaded();
preloader._visible = true;
if (loaded != filesize) {
preloader.preload_bar._xscale = 100*loaded/filesize;
} else {
preloader._visible = false;
if (picture._alpha<100) {
picture._alpha += 10;
}
}
};
function nextImage() {
if (p<(total-1)) {
p++;
if (loaded == filesize) {
picture._alpha = 0;
picture.loadMovie(image[p], 1);
desc_txt.text = description[p];
picture_num();
}
}
}
function prevImage() {
if (p>0) {
p--;
picture._alpha = 0;
picture.loadMovie(image[p], 1);
desc_txt.text = description[p];
picture_num();
}
}
function firstImage() {
if (loaded == filesize) {
picture._alpha = 0;
picture.loadMovie(image[0], 1);
desc_txt.text = description[0];
picture_num();
}
}
function picture_num() {
current_pos = p+1;
pos_txt.text = current_pos+" / "+total;
}
function thumbNailScroller() {
// thumbnail code! 
this.createEmptyMovieClip("tscroller", 1000);
scroll_speed = 10;
tscroller.onEnterFrame = function() {
if ((_root._ymouse>=thumbnail_mc._y) && (_root._ymouse<=thumbnail_mc._y+thumbnail_mc._height)) {
if ((_root._xmouse>=(hit_right._x-40)) && (thumbnail_mc.hitTest(hit_right))) {
	thumbnail_mc._x -= scroll_speed;
} else if ((_root._xmouse<=(hit_left._x+40)) && (thumbnail_mc.hitTest(hit_left))) {
	thumbnail_mc._x += scroll_speed;
}
} else {
delete tscroller.onEnterFrame;
}
};
}
function thumbnails_fn(k) {
thumbnail_mc.createEmptyMovieClip("t"+k, thumbnail_mc.getNextHighestDepth());
tlistener = new Object();
tlistener.onLoadInit = function(target_mc) {
target_mc._x = hit_left._x+(target_mc._width+5)*k;
target_mc.pictureValue = k;
target_mc.onRelease = function() {
p = this.pictureValue-1;
nextImage();
};
target_mc.onRollOver = function() {
this._alpha = 50;
thumbNailScroller();
};
target_mc.onRollOut = function() {
this._alpha = 100;
};
};
image_mcl = new MovieClipLoader();
image_mcl.addListener(tlistener);
image_mcl.loadClip(thumbnails[k], "thumbnail_mc.t"+k);
}