I have a friend who has a major crush on this other guy at school,she is so obssessed with him but the thing is the guy kinda has a crush on me he talks to me on facebook and he even calls me ,I am not interested in dating him he is just a friend,should I tell my friend about this?
I don't think so. It's not going to do any good. She will still have a massive crush on him - It's not something you can switch off easily - and might be jealous of you. You don't have to feel bad about it. You're not doing anything wrong.
It might be best not to meddle in others' relationships. If things go wrong, and someone gets hurt, you might end up being blamed, when you were only trying to help.
No need to tell her.... he is a friend.... as I am sure she already knows. Do take care not to get at all involved though. By that I mean no taking messages or anything like that... and , if I were you, I would not talk about one with the other either. If you do you will just be in the middle of a potentially horrid situation. Smile politely and change the subject if one starts to talk about the other. That is a good way to keep both as friends.