<html class="reftest-wait"> <head> <script> function boom() { document.body.offsetHeight; var parent = document.getElementById("body"); var newdiv = document.createElement("div"); newdiv.appendChild(document.createTextNode("5")); parent.appendChild(newdiv); document.body.offsetHeight; document.documentElement.className = ""; } </script> </head> <body id="body" onload="boom();"> <div>1</div> <div>2</div> <div>3</div> <div>4</div> </body> </html>