Dynamically created thumb gallery - properties of previous thumb?

Hello, everyone!

I have this dynamically created thumb gallery from a XML:

function loadXML(loaded) {
if (loaded) {
xmlRoot = this.firstChild;
total = xmlRoot.childNodes.length;
imageBig = [];
imageThumb = [];
imageTitle = [];
imageDesc = [];
for (i=0; i<total; i++) {
imageBig* = xmlRoot.childNodes*.childNodes[0].firstChild.nodeValue;
imageThumb* = xmlRoot.childNodes*.childNodes[1].firstChild.nodeValue;
imageThumb_fn(i);
}
}
else {
content = “file not loaded!”;
}
}

function imageThumb_fn(k) {
parent.thumbs.createEmptyMovieClip("thumb"+k, _parent.thumbs.getNextHighestDepth());
tlistener = new Object();
tlistener.onLoadInit = function(target_mc) {
target_mc._x = (target_mc._width + 18) * k;
target_mc._y = 0;
}
}

Is there any way to get _x and _y properties of a previously created thumb (e.g. k-1) and use them in maths of a position of current thumb??