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

function boom()
{
  var b = document.body;
  b.contentEditable = "true";
  document.execCommand("contentReadOnly", false, null);
  b.focus();
  b.contentEditable = "false";
  document.documentElement.contentEditable = "true";
  document.createDocumentFragment().appendChild(b);
  document.documentElement.focus();
}

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