Nested xml Flash8

I creating a portfolio that has a thumbnail menu. When you click on the thumbnail, a preview image show with 1 to 10 buttons under it that opens up detail images of that project.

Main question, How do I access the nested detail images in the xml from flash.

So my xml looks like this:

<heading>heading 01</heading>
<description>Lorem ipsum dolor sit </description>
<link> <a href="</link>
<heading>heading 02</heading>
<description>2 orem ipsum dolor sit </description>
<link><a href="</link>

Flash file looks like this:

function GeneratePortfolio(xmlData) {
xmlNode = xmlData.firstChild;
heading = [];
thumb = [];
preview = [];
description = [];
//bigImage = [];
//link = [];
total = xmlNode.childNodes.length;
for (var i = 0; i < total; i++) {
var currentPicture = portfolioPictures*;
heading* = xmlNode.childNodes*.childNodes[0].firstChild.nodeValue;
thumb* = xmlNode.childNodes*.childNodes[1].firstChild.nodeValue;
preview* = xmlNode.childNodes*.childNodes[2].firstChild.nodeValue;
description* = xmlNode.childNodes*.childNodes[3].firstChild.nodeValue;
//link* = xmlNode.childNodes*.childNodes[4].firstChild.nodeValue;
//bigImage* = xmlNode.childNodes*.childNodes[5].firstChild.nodeValue;
How do I add in bigimages nested bigimage