How to make him like me without seeming too forward?

Okay so ive never had a boyfriend and im 15 and i realllllly like this guy in my cl. I always smile at him when i walk past him in the corridors and he smiles back, but im getting the feeling hes only doing it to be polite and just to get by. Ive caugt him looking at me a few times in cl and when i look over at him he always looks at me. Is this just coincidence or does he like me? Im so confused! We like never talk at school becuase we hang out in different groups to each other, but whenever he needs help and im on msn he always comes to me with his problems and i hellp him out like we talked once for 2 hours straigt on msn and he was saying how funny i was/ is there a chance he likes me? we also were talking about our childhood and he said that we should talk again some time but that was like last month but a few weeks ago we talked about getting jobs and stuff for like an hour. i feel awkward at school coz i have nothing to talk about with him