Actionscript not loading XML into Dynamic Fields

I am working on a project where I am reading (trying to!) from an xml file. I have 5 separate dynamic text fields that I am filling with the individual digits from a string. I am not an expert but really think my code should work. Below is the actionscript and the xml I am using.

import fl.controls.*;

var digit01_xml:XML;
var xmlReq:URLRequest = new URLRequest("testRBS.xml");
var xmlLoader:URLLoader = new URLLoader();

xmlLoader.load(xmlReq);
xmlLoader.addEventListener(Event.COMPLETE, xmlLoaded);

function xmlLoaded(event:Event):void
{
digit01_xml = new XML(xmlLoader.data);
var mystring:String = digit01_xml.RicohRewards[0].tokens[0];
d01_txt.text = mystring.charAt(1);
d02_txt.text = mystring.charAt(2);
d03_txt.text = mystring.charAt(3);
d04_txt.text = mystring.charAt(4);
d05_txt.text = mystring.charAt(5);
}

<?xml version="1.0" encoding="utf-8"?>
<RicohRewards>
<show>1</show>
<percentage>25</percentage>
<tokens>0102347</tokens>
</RicohRewards>

Any help would be much appreciated!