Error Pop up in WP7

I want to show a pop up to a开发者_StackOverflow社区 user when he want to submit a text on a textbox and click on a button to submit it. If for example he want to save a wrong text or something like that.

Or just try a MessageBox.

If you need a custom control, you could also use the silverlight 3 child window control with the windows phone 7. It animates nicely, and since it is part of the silverlight dlls it is not third party.

Using child window in windows phone 7