popup.xul

<?xml version="1.0"?>
<?xml-stylesheet href="chrome://global/skin/global.css" type="text/css"?>
<window id="popup-window"
        xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
        title="FOO"
        windowtype="popup"
        width="640" height="480"
        persist="screenX screenY width height sizemode">
<browser flex="1" src="http://google.com/"/>
</window>