Accessing Function from another timeline

1

Hi,

I’m trying to access this function from another timeline. This function resides on the root level and I want to access it from a button within an MC on the main timeline. How can I do this?

vol_onBTN.onRelease = function() {
       	vol_offBTN._visible = true;
		vol_onBTN._visible = false;
	   if (soundTrack.playing) {
                clearInterval(sndObj.interval);
                soundTrack.interval = setInterval(soundTrack, "fadeOut", 200/12, 1);
        }
};