I have a crush on my teacher but I don't want anything more than a student-teacher relationship. I'm not sure how I'm going to cope when I leave. I just want to keep in contact. I care about him and just want to make sure he's happy. What do I do?

You really shouldn't be pursuing interests with a teacher. If something like that were to get out they could lose their job. And that's not something that they are going to be happy about.

after and only after you have left the class/graduated you could always add him on facebook. Just make sure you're not giving the wrong idea.