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

function boom()
{
  document.body.__lookupSetter__("textContent").call(document.body);
}

</script>
</head>
<body onload="boom();"></body>
</html>