Does he like me or not?

I've known this guy for 2 years yet i've never talked to him before. He's 1 grade higher than me and i see him alot in the corridors. Last year, at this christmas party, me and my friend went across him and he asked me which grade I was in. When he went back in the clroom, his friend told me he thought I was pretty.I don't know if its true tho... And everytime are eyes meet, he looks away real quickly and continues to talk to his friend. I added him on facebook and on msn and i've talked to him from time to time, like "Hello" and such.. He would answer me like this "Hello......". I have a feeling he hates me or something.. What do you think?