<html xmlns="http://www.w3.org/1999/xhtml" xmlns:xul="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
<head>
<script>
function boom()
{
var menulist = document.createElementNS("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul", "menulist");
document.getElementById("h").appendChild(menulist);
}
</script>
</head>
<body onload="boom();">
<xul:listboxbody><xul:hbox id="h"/></xul:listboxbody>
</body>
</html>