<?xml version="1.0"?>

<?xml-stylesheet href="chrome://global/skin/" type="text/css"?>

<window id="example-window" title="Example XUL 1.0"
        xmlns:html="http://www.w3.org/1999/xhtml"
        xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
       
<description>
  This is just some test text.
</description>

</window>

...