I'm having a horrible time figuring out how to resize my user interface without it reverting back to windowed mode.

Am I stuck downloading a user interface mod or is there a way to get the blizzard UI to cooperate with me?

This is what it looks like as of now:



And, for those of you wondering, I'm playing on a 50" Plasma TV at 1366 x 768 resolution.

Any help would be greatly appreciated!