I like a guy!?

well, i like a guy and he knows it. everything was normal for on day then things started getting weird. he never ims me neither does he say hi. i do the same but i want to forget him but i cant. what should i do and how should i act around him. i mean i like him but i dont know his feelings. i mean yesterday at my school dance my two friends asked him if he wanted to dance with me and he said no. what does that mean.?? i dont know wat to do and how to act around him i mean i get red and he knows it... helpp