Making A Button Flicker

programming flash
1

Hi all, onRollOver I am trying to make my button Flicker on/off but cannot get it too work, the best I can do is get it to go to alpha 60 and then back to 100…

newBut.onRollOver = function() {
			if( cnt < 100){
// Reduce alpha.
// Lower this for more dramatic effect.
this._alpha = 60;
this._alpha = 100;
cnt++;}}

Thanks in advance!