Getting a Checkbox's value from an outside class

Hi,

I have a ball vector object which i generate from its own class in as3, but i wish to base its behaviour on the state of a checkbox called “walls”. Which is at a “sideways” class, (see attached below). Such that the ball will reverse direction if it reaches the edges of the stage when the checkbox is ticked.

The walls check box is in the controlpanel class

Can anybody suggest some way for the ball class to get the state of the checkbox, I can’t figure out how to do this by going back up the class heirarchy or by using listeners.(-: