<!DOCTYPE html> <html class='reftest-wait'> <head> <style> fieldset:invalid { display: none; } </style> </head> <script> function onloadHandler() { document.getElementById('i').readOnly = false; document.documentElement.className = ''; } </script> <body onload='onloadHandler();'> <fieldset id="fieldset"> <input id='i' required readonly> </fieldset> </body> </html>