Help with Maze, CD, and getBounds

I pieced together some code using getBounds and I have made a simple little maze thing.

What I can’t do, which is the ultimate goal of this program, is to put MCs around the stage and have various things happen when the moving ball MC passes over them. But I can’t get that to happen. There’s one in the Walls MC and one just out on the stage.

I’m attaching the fla so maybe someone can find my simple error.