<!DOCTYPE html> <!--fieldset with one valid element and invalid one is added dynamically --> <html class='reftest-wait'> <head> <style> fieldset:invalid { display: none; } </style> </head> <script> function onloadHandler() { document.getElementById("fieldset").appendChild(document.getElementById('i')); document.documentElement.className = ''; } </script> <body onload='onloadHandler();'> <input id='i' type='email' value='bar'> <fieldset id="fieldset"> <input id='j' type='text' value='foo'> </fieldset> </body> </html>