That happened to me one time...the professor didn't show up, so we all waited for about half an hour and left. We came back next time...no professor. Someone had checked with the dean's office and they said they didn't have anyone to teach that section but they would find someone shortly so we should just come to the next meeting of the class. To make a long story short, they never did find anyone to teach than damn class so I ended up having to take it at night. But hey, at least it got me out of a class with a girl whose boyfriend I made out with not long before that.
