 <pre><code>iframe.style.visibility="hidden"; </code></pre> <p>and to show it:</p> <pre><code>iframe.style.visibility="visible"; </code></pre> <p>Edit: And you can use the onsubmit="JavaScriptCode" event to trigger the change.</p> <p>Reference: <a href="http://www.w3schools.com/jsref/event_form_onsubmit.asp" rel="nofollow">http://www.w3schools.com/jsref/event_form_onsubmit.asp</a></p>