How do i make an object to move on the edge?

Hi guys i am making a turn based board game where a player can only move on the edge of the board as shown by the red spots.They cannot move in the black or white area.Please tell me a way to do it i cannot find a solution.I have attached the image.Thanks

I can try to help, I did something like this a while back. Are they supposed to move after clicking on a spot, or move with the arrow keys, or ?

tokens will be selected on mouse click and are supposed to move when clicked on spot...

Sorry I am kind of tight on time at the moment... I will have to give it another shot later.

What I am trying to do is use a bullet behaviour for the tokens. On click, the token would first "bullet" to the new "X" position, then "bullet" to the new "Y" position (so the tokens move in 4 directions only). I suppose this could be done with 8-direction also. I guess it depends on your preference (and what other things the game will be doing).

Perhaps you will end up figuring it out before I get back to it =)

thanx man...i will try and wait for your reply