Thanks Ray, I set it up but no results. Here's what I did:
<div id="afterSubmit" style="display:none;"> Your request has be submitted successfuly </div>
<form class="Basic580_Default" id="roacontact_Basic580_Default" name="roacontact_Basic580_Default" method="post" action="<?php echo (htmlentities($_SERVER["PHP_SELF"], ENT_QUOTES)); ?>" onsubmit="document.getElementById('afterSubmit').style.display = 'block';">
The rest of the form follows. Can you determine what I did wrong?