<html xmlns="http://www.w3.org/1999/xhtml" xmlns:xul="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">

<head>

<bindings xmlns="http://www.mozilla.org/xbl">
  <binding id="lc">
    <content>
      <xul:listcell> t <children/></xul:listcell>
    </content>
  </binding>
</bindings>

<script>
function boom()
{
  var hbox = document.createElementNS("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul", "hbox");
  document.getElementById("vv").appendChild(hbox);
}
</script>

</head>

<body onload="boom();">

<div style="-moz-binding: url(#lc);" id="vv"></div>

</body>

</html>