XML.idMap Issue (urgent)

programming flash
1

I have successfully loaded and parsed the XML file and can trace the nodes with this code from the live docs:

var readXML = new XML();
readXML.load("spaces.xml");
readXML.onLoad = function(success) {
    myXML = new XML();
    myXML.parseXML(readXML);
    for (var x in myXML.idMap){
        trace('idMap.' + x + " = " + newline + myXML.idMap[x]);
        trace('____________' + newline);
    }
}

The problem is that when I use .firstChild or .childNodes[0]; i get undefined. Does anyone know how to access nodes inside a node referenced in the idMap?