Mixed signals and now i'm confused?

this guy i know is giving me mixed signals. One night i was talking to him over IM and we started playing truth or dare and he asked who I liked. i told him i liked him and he said okay. we talked for a few minutes after that and then we both logged off. the next day he sat next to me in writing and we were playing around and talking. we did this the next day too. Then after that, he wouldnt answer my IMs and he hasn't said anything to me in school. He left school today before i had a chance to talk to him and now i don't know what to do. i really like him and i want to know if he likes me back. what can i look for to see if he likes me?