How can i use the google shortener js api in xul?

hi,

i want to try this example http://code.google.com/p/google-api-javascript-client/wiki/Samples in xul. How must i do it?

Where must i place this code?
<script src="https://apis.google.com/js/client.js?onload=load"></script>

I put it on the browser.xul file, but the function "load" didnt work. instead i try "?onload=myaddon.load" but it didnt works.

<?xml version="1.0"?>
<?xml-stylesheet href="chrome://mysaddon/content/browser.css" type="text/css"?>
<!DOCTYPE overlay SYSTEM "chrome://mysaddon/locale/lang.dtd">
<overlay xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
<script src="chrome://myaddon/content/browser.js" type="application/javascript"/>
<script src="https://apis.google.com/js/client.js?onload=load"></script>

But i have more problems to use the google api in xul. have somebody a good tutorial, example code?

best regards
ebody