stop and start video commands?

Hi

I have a video that I imported at the 10 second mark of my composition.

I clicked on the video on the stage, and I opened the Actions panel where I added a click event:

sym.stop();

However when the movie is clicked on when the comp runs nothing happens, it still continues to run.

Anyone know how to do this? Ideally I'd like to make a button that toggles the text "video on/off" but for now I'd just like the sanity of knowing why this super simple click is not working.

Thanks,

Rich