Why is he ignoring me all of a sudden?

We were very close friends through net(though we knew each other earlier too thru some mutual frnds but had never actually met) and shared everything abt ourselves. And then we decided to meet and all of a sudden he turned cold towards me. He completely started ignoring me without any reason. It is hard to believe that a guy who had asked u out nd even picked a fight wid a frnd of his for u has started ignoring u without any reason.I never did anything wrong and i think im fairly good looking with a pleasant personality. And im sure of it that hez nt going arnd wid neone else coz i confirmed it. I dont want him 2 like me but i just want 2 know the reason y he is doing this. Wat is the reason?