How to land an ollie! please help!?

okay im trying to land an ollie on a skateboard and i tried it on the gr and on carpets and its easy but when i did it on pavement i BUST MY AZZ!!! like i was cruising and i tried to do an ollie and the board literally went flying out from under me!!!! so what did i do wrong??? and i tried it like 40 times and i still cant land one b/c the same thing keeps happening!! whats your advice?? and do i really have to start out tricks with ollies or is there other easier tricks to do?? please help