Barricades for a labyrinth game in flash cs5

hi, i am trying to create a labyrinth game for the iphone. It uses the accelorometer and i have written the code for that and the holes, but i cant figure out how to write it so i could have something to stop my ball moving, like a wall? i have tried hitTestPoint , but it keeps popping up error messages. im new to this and i have allready started in actionscript 3.0 and dont want to have to revert to actionscript 2 if possible.

Thanks