Trouble with tree component with XML

I’ve been trying to figure this out for past 2 days and can’t find a single tutorial or example anywhere.

Here’s my code:

myTreeDP = new XML();
myTreeDP.ignoreWhite = true;
myTreeDP.load(“categories.xml”);
myTreeDP.onLoad = function() {
myTree.dataProvider = myTreeDP;
};
myTreeListener = new Object();
myTreeListener.change = function(evt:Object) {
url = evt.target.selectedNode.data;
MC_blank.loadMovie(url);
};
myTree.addEventListener(“change”, myTreeListener);

What I’m trying to do is play an external .swf (defined in “data” attribute in XML file) inside an empty movieclip when the user clicks on a LEAF node. With the code above (which I found somewhere) the movie attempts to play when user clicks on ANY node, but that’s not what I need.

I also get this error message when a node is clicked:
Error opening URL “file:///D|/test/undefined”

Paths are set correctly.

I figure this should be pretty simple but I’m not very familiar with AS.

I’m about to go nuts. Thanks in advance for any help!