How to change the game-window style?

I need an untitle window,like the full-screen I try to use winAPI: FindWindow -> SetWindowLong -> MoveWindow (To [0,0]) Now, it looks very good, but the Exit button does not focus on the button! it's out of the button. look:

Anyone has solution?

or visit:http://forum.unity3d.com/threads/85981-Is-there-a-way-to-Change-button-s-focus-position-Look-this-problem...