<!DOCTYPE html>
<html>
<head>
<script type="text/javascript">

function boom()
{
  var a = document.documentElement;
  var b = document.body;

  document.removeChild(a);
  b.contentEditable = "true";
  document.appendChild(a);

  function t() {
    document.removeEventListener("DOMAttrModified", t);
    document.removeChild(a);
  } 

  document.addEventListener("DOMAttrModified", t);
  document.execCommand("insertunorderedlist", false, "<h1>");
  document.removeEventListener("DOMAttrModified", t);
}

</script>
</head>

<body onload="boom()"></body>
</html>
