Tilebased game: collision detection problem

hi,

im making a game in isometric view, but ive got some problems with the collision detection… my char moves around but the collision detection doesnt works… ive read some tutorials on tonypa.pri.ee about tilebased games and collision detection, but he only uses collision detection in 2d array maps and i want to use it in 3d array maps…
could someone help me plz with the collision detection:) because it working at all
(i know i dont use 3d arrays untill now but im still working on it:smirk: )

this is my code so far(its in the attachment)