Collision detection "game map"

Hi there. I’ve got a slight problem, maybe you could help me…

scene:
- a ‘person’ / object
- a map

the map has wholes and edges on it AND is placed in a 45/45/45 degree angle.

Problem:
I want to do a collisioncheck between the ‘person’ and the map. All that to accomplish the person not walking off the map.
The HitTest option from flash does not resolve my problem because it does not look at the content of the movie but the boundingbox.

I’m sorry, my english is not that good as it should be, i’m from the netherlands…

Thanks in advance