maze wall algorithm

[N Cueto]

This is a puzzle more than a RunRev
topic. Apologies.

If given a maze in the form of a
grid such as this...
 _ _ _
|1|2|3|
|- - -|
|4|5|6|
|- - -|
|7|8|9|
 - - -

... and in which the squares 
are made up of images and the
walls of graphics...

... and also in which the
walls are removable so as
to create a maze such as
this...

 _   _
|1 2|3|
|  - -|
|4|5|6|
|  - -|
|7 8|9|
 -   -

... then, what would be the 
ideal scripting for limiting
"movement" between only
contiguous squares that are
not separated by a wall, i.e,
in this example the only
allowed path would be...

8->7->4->1->2

My own idea is to use either
the loc of objects or custom
properties.

Many many thanks.

--
Nicolas Cueto
niconiko language school