You can edit / change the code and click run button <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <style> input[type=text]:enabled { background: red; } </style> <script>var clicky_site_ids = clicky_site_ids || []; clicky_site_ids.push(101319977);</script><script async src="//static.getclicky.com/js"></script> <form action=""> First name <input type="text" value="Tom"><br> Last name: <input type="text" value="Jerry"><br> Age: <input type="text" disabled value="No one knows"> </form>