Changing onRelease to onRollover doesn't work in this script

1

I need a rollover function and so I changed onRelease to onRollover but the rollover effect then doesn’t work. Can’t fugure out why. Please help.

  • Script is on seperate layer (on root)
  • hit_mc is the movie clip on which the rollover should work
  • mask_mc is the one that should tween when mouse goes over hit_mc

hit_mc.onRollover = function() {
tweenBall(mx.transitions.easing.Regular.easeOut);
};

function tweenBall(easeType) {
var begin = 17;
var end = 200;
var time = 15;
var mc = mask_mc;
ballTween = new mx.transitions.Tween(mc, “_y”, easeType, begin, end, time);
}