What is this film called?

Ok I seen this film years ago but I forget the name! Its about this wee boy who rides his bike late at night down to like a library and when he's in the library something happens, like he falls and gets knocked out. And the next scene shows him in like a different world sort of (I can't really remember) but then it just shows him wakening up at the end of the film to realise it was all just a dream after he was knocked out? Please help, I wanna watch this movie again! 10 easy points to get!