Ah, I'm back home with my laptop. It is ctrl+alt+directional key (up). I don't really use the feature, but it has it's merit. I'm guessing this should work for you. If not, here's what you can do: Simply take your monitor and position the base very delicately so that it is now perfectly straight above the so called "top" of your monitor. Be sure that the "top" lies flat on your desk.
In lamens terms, flip the biitch.