Example Window
<?xml version="1.0"?> <?xml-stylesheet
href="chrome://global/skin/xul.css“
type="text/css"?>
<!DOCTYPE window>
<window id="main-window“
xmlns:html=http://www.w3.org/TR/REC-html40
xmlns="http://www.mozilla.org/keymaster/gatek
eeper/there.is.only.xul">
 <menubar><menu name="File">
 <menuitem name="Hello World!"
onclick="dump('Hello world!\n');"/></menu>
 </menubar> <html:iframe id="content-frame"
src="contentframe.html" flex="100%"/>
 </window>