title: Fix an element inside an iframe in the center of the screen
body: <p>I have an iframe embedded inside a fan page of FB, and I want to show a fixed box (like a dialog box) at the center of the screen.</p>
  <p>How can I do that?</p>
  <h3>UPDATE</h3>
  <p>Look at Work For Us app:</p>
  <p><a href="http://www.facebook.com/DiscoverIntel?ref=nf&amp;sk=app_404596412628" rel="nofollow noreferrer">http://www.facebook.com/DiscoverIntel?ref=nf&amp;sk=app_404596412628</a></p>
  <p><img src="https://i.stack.imgur.com/0Ipo0.png" alt="enter image description here" /></p>
  <p>When I click in the green button behind (named &quot;Apply for this position&quot;) it always shows the &quot;Thank you&quot; dialog at the center of the screen.</p>