Ridiculously simple button question

I’ve got a button inside a movie clip, which is inside another mc on the main timeline. I would like it to trigger a third mc which is also on the main timeline. The instance of this third mc is named DoublePay.

I’ve got this script on the button

on (release){
_root.DoublePay.gotoAndPlay(1)}

and nothing happens. I know this is an easy one but I am stumped. Any help would be appreciated.