Hide User Interface?

Could someone please tell us how to Hide the User Interface while we play? Hiding the User Interface would help a lot when we record movies. Thanks!

Just close all those windows.

There's an option in the options... set any key to it...
[Link]

What about the top-right interface. I don't see a button for that?

It's the whole thing, assign that option to a key, say, F1 then press F1, bamn! All windows are gone.