HELP: Control MCs with AS placed on the timeline

1

Hello,

I have a question on how to control an MC using AS which is placed in the timeline.

Here is the scenario:
I have an MC named “backMC” placed on the main stage. My other MC named “showcase” is also placed in the main stage on a different layer. On “showcase” last frame, I wanted to add an AS that would make my “backMC” play.

I tried to add this AS on the last frame of “showcase” but didn’t get any result.

_parent.backMC.gotoAndPlay(“up”);

Question:
Am I doing things right? Or is it not possible to control it my way?

Thank You