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.

How can I do that?

### UPDATE

Look at Work For Us app:

<http://www.facebook.com/DiscoverIntel?ref=nf&sk=app_404596412628>

![enter image description here](https://i.stack.imgur.com/0Ipo0.png)

When I click in the green button behind (named "Apply for this position") it always shows the "Thank you" dialog at the center of the screen.