<!DOCTYPE HTML>
<html>
<head>
<script type="text/javascript">
function init() {
  // This will throw a HierarchyRequestError exception
  var doc = document.implementation.createDocument(null, 'DOC', null);
  doc.documentElement.appendChild(doc);
}
window.addEventListener("load", init);
</script>
</head>
<body>
  Testcase for bug 415498. This page should show an exception in Error Console on load
</body>
