<!DOCTYPE html> <html class="reftest-wait"> <head> <style> #checkbox { position: absolute; left: 0px; top: 0px; background: -moz-linear-gradient(left, white, brown); } #toremove { position: absolute; left: 0px; top: 0px; width: 100px; height: 0px; background: black; } </style> </head> <body> <div id="checkbox"> <input type="checkbox"> </div> <div id="toremove"> </div> </body> <script type="text/javascript"> var checkBox = document.getElementById("checkbox"); var toRemove = document.getElementById("toremove"); toRemove.style.height = checkBox.offsetHeight / 2 + 0.2 + "px"; function boom() { toRemove.parentNode.removeChild(toRemove); document.documentElement.className = ""; } window.addEventListener("MozReftestInvalidate", boom, false); </script> </html>