<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 listbox = document.getElementById("listbox");
var td = document.getElementById("td");
var listitem = document.createElementNS(XUL_NS, "listitem");
listbox.appendChild(listitem);
listbox.appendChild(td);
}
var XUL_NS = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
</script>
</head>
<body onload="boom();">
<table><tbody><tr><td id="td">X</td></tr></tbody></table>
<xul:listbox id="listbox"/>
</body>
</html>