<!DOCTYPE html>
<html>
<head>
<script>

function boom()
{
  var root = document.documentElement;

  while (root.firstChild) { root.removeChild(root.firstChild); }

  var body = document.createElementNS("http://www.w3.org/1999/xhtml", "body");
  var div = document.createElementNS("http://www.w3.org/1999/xhtml", "div");
  root.contentEditable = "true";
  root.appendChild(div);
  root.removeChild(div);
  root.insertBefore(body, root.firstChild);

  window.getSelection().removeAllRanges();
  var r0 = document.createRange();
  r0.setStart(body, 0);
  r0.setEnd(body, 0);
  window.getSelection().addRange(r0);
  var r1 = document.createRange();
  r1.setStart(div, 0);
  r1.setEnd(div, 0);
  window.getSelection().addRange(r1);

  document.execCommand("inserthtml", false, "1");
}

</script>
</head>

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