Disable or lose focus on a movieclip

Say I have a movieclip which i code to act as a button. Upon clicking this button, a transparent movieclip appears located over the original button movieclip. The onRollOver event on the lower, button movieclip is still re-acting to the mouse.

Is it possible for set the "focus" to the transparent movie clip? I guess I could code the onRollOver event to check if the other movie clip is shown before it runs the code in its event.