Why won't he get the hint?

There is a boy in my school, he is in my form and hes called ben. I really like him and I have tried everything to try and get him to catch on but he just doesn't seem to get it. It all started on facebook one night he just suddenly popped up on chat and then it went from there. After he started confiding in me like he told me his parents had split up and when he broke up with my evil ex best mate I was so happy but I knew he wouldn't be so I chatted to him on facebook and said that any girl would be lucky to have him and even I don't deserve him. He then got put next to me in geography and then I basically did his work for him well I told him what countries were what. Then he went out with this other girl and I was gutted but then he broke up with her so I said the same thing to him as I'd done last time. I really want him to ask me out but he isn't getting it and now he isn't answering me. What should I do ?