XML Parsing in AS Class...Root Node undefined

Upon parsing XML via an AS class called XMLMenu I created (an extension/modification to Senocular’s code), I want to save the root XML node/structure to use later.

Here is the relevant code:

 // class var to save root node to...
private var menuNode:XMLNode;

public function XMLMenu(xmlURL:String, container:MovieClip, x:Number, y:Number) {
	this.container = container;
	this.x = x;
	this.y = y;
	menuXML = new XML();
	menuXML.ignoreWhite = true;

	menu = container.createEmptyMovieClip("menu", container.getNextHighestDepth());
	submenu = menu.createEmptyMovieClip("submenu", menu.getNextHighestDepth());

public function loadXML(xmlURL:String):Void {
	var menuClass:XMLMenu = this;
	menuXML.onLoad = function(success) {
		if (success) {
			menuClass.createMenu(menuClass.getX(), menuClass.getY(), this.firstChild, true);
			menuClass.menuNode = this.firstChild;
			trace("Menu Node: " + menuClass.menuNode);
		} else {

public function getBoxNum(name:String):Number {
	trace("Menu Node: " + menuNode); // IT'S UNDEFINED HERE!
	return searchNodes(menuNode, "item", name);

I have access to the menu class in my loadXML procedure so I know that’s not the issue. But as soon as I get out of this method and try
to refer to menuNode (in the getBoxNum() function), I get an undefined. What am I missing?

Thanks for the help,