insertmultiple.html

Enable keyboard shortcuts

<html class="reftest-wait">

<head>

<script>

function boom()

  document.body.offsetHeight;

  var lastdiv = document.getElementById("last");

  var parent = lastdiv.parentNode;

  for (var i = 2; i <= 4; i++) {

    var newdiv = document.createElement("div");

    newdiv.appendChild(document.createTextNode(i));

    parent.insertBefore(newdiv, lastdiv);

  document.body.offsetHeight;

  document.documentElement.className = "";

</script>

</head>

<body onload="boom();">

<div>1</div>

<div id="last">5</div>

</body>

</html>