<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script>
function boom()
{
document.getElementById("i").appendChild(document.createElementNS("http://www.w3.org/1999/xhtml", "div"));
}
</script>
</head>
<body onload="boom();">
<div><span><span id="i"><div></div></span></span></div>
</body>
</html>