ExternalInterface not returning chinese characters

Question

I've got a Flex application embedded in a PDF.  Also in that PDF is a field (hidden text field) called Data containing XML that happens to contain chinese characters.  The encoding for the XML data is UTF-16. To retrieve the data, I make a JS call (getData) using ExternalInterface.  The JS is simple:
function getData()
  var data = this.getField('Data').value;
  return data;
I also inserted before the return an alert to display the data.  The chinese characters were present and displaying as expected:
In my flex application I make the following call:
var resultXML:XML = XML(ExternalInterface.call("getData"));
However, the resulting XML appears to not be read as UTF-16, and the characters displayed look like:
Is there something special I have to do to get the chinese characters correctly passed through from the ExternalInterface call?

Answer 1

    OK, did not know that "Arial Unicode MS" font is only distributed with Microsoft Office, was looking into relying on this font in case if "simsun.ttc" font is not available at the user's system, by using the following:
<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
               xmlns:s="library://ns.adobe.com/flex/spark"
               xmlns:mx="library://ns.adobe.com/flex/mx"
               minWidth="1024" minHeight="768"
               creationComplete="resourceManager.localeChain = ['zh_CN']"
               layout="{new VerticalLayout()}">               
    <fx:Style>
        @namespace s "library://ns.adobe.com/flex/spark";
        @namespace mx "library://ns.adobe.com/flex/halo";
        s|Label {
            fontFamily: "Arial Unicode MS, SimSun, Arial";            
    </fx:Style>   
    <fx:Script>
        <![CDATA[
            import spark.layouts.VerticalLayout;
        ]]>
    </fx:Script>
    <s:Label id="sparkLabel" text="伜-伞伟传伡伢伣伤伥伦伧伨伩伪伫伬伭-伝"/>   
</s:Application>  
Tough decision ahead, but accordingly to  the survey at codestyle.org (2000 participants from 2007 year and onwards), Arial Unicode MS is present at 62.53%% system surveyed.
ps
   My current install of Windows XP already includes the install of Microsoft Office 2007 and I've also enabled/disabled the support of East Asian languages, thus the content of  my "fonts" folder differs now significantly from "clean" Windows XP install version.
Nevertheless I found the page with comprehensive lists of standard fonts installed with different releases of Windows that looks viable here:  http://www.kayskreations.net/fonts/fonttb.html