<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<script>
function boom() {
  setTimeout(function(){
    var o=document.getElementById('b');
    document.getElementById('a').appendChild(o.parentNode.removeChild(o));
  },0);
  var o=document.getElementById('c');
  var p=document.getElementById('b');
  p.id=[o.id, o.id=p.id][0];
  o=document.getElementById('b');
  o.setAttribute('sandbox', 'disc');
  window.location.reload(true);
}
</script>
</head>
<body onload="boom();">
<header id='a'></header>
<output id='b'></output>
<iframe id='c' sandbox='allow-same-origin' src='http://a'></iframe>
</body>
</html>