Start Over after idle

I`m not sure what a kiosk movie is, but something like this might work

function init() {
oldX = this._xmouse;
oldY = this._ymouse;
}
init();
function checkMousemove() {
if (this._xmouse == oldX && this._ymouse == oldY) {
clearInterval(myInterval);
gotoAndStop(1);
} else {
oldX = this._xmouse;
oldY = this._ymouse;
//you might want to clearInterval here and put the setInterval in a startbutton press or something.
}
}

myinterval = setInterval(checkMousemove, 120000);