Make a popup

I made an goldmine and I am trying to make a popup window at the bottom at the screen. So if I push the mine a window will popup at the bottom of the screen, I still want to see the background. Someone know how to do this?
I am using C#

http://docs.unity3d.com/Documentation/Manual/GameInterfaceElements.html

http://www.tasharen.com/?page_id=140