How did you get stuck? Were you able to go to other rooms first, or did you just immediately get stuck on the roof? If you quit the game and reload it, it should take you back to the main map. (It saves automatically after time passes.)
The only place I could select is the roof. Edit: oh! I can click on the cafeteria. But that is also just about it.
Edit2: Aha, I see what went wrong. I was playing with full screen, and the scroll bar on the side doesn't show up. I just became aware of the scroll bar.
