Movement with Field of Vision problem

Basically, I have a circle that moves around with the use of the keyboard arrow keys, and stops when it touches certain objects. I have a giant black square that follows it with a transparent area in the middle, which is where the circle is located, creating a field of vision the user is able to see (see attachment). I cant put this blackness on the same clip as the circle, or my walls take no effect since the blackness would always be touching the walls. When I put the movement script on a seperate movie clip with the blackness so that would move the same as the circle, the movie clip containing the blackness continues moving while the circle is running into a wall because theres no script that effects it when walls are touched, cause it’s always touching them so I cant make one! :vamp: How can I make the blackness stop as well when the circle does?