MC scaling

Hi I’m trying to modify the code below.
I have two movieclips on the stage.

When you rollover the mc I want it to scale and zoom back to original size on mouse out.
When you click on it I want it to stay scaled.
When you rollover another mc I want the mc that was scaled to zoom back to it’s original size.

MovieClip.prototype.zoomInAndOut = function(n, s) {
this.speed = s;
this.scale = this._xscale;
this.zoom = function(d, s) {
this.onEnterFrame = function() {
if ((this.scale>=100*n && d == 1) || (this.scale<=100 && d == -1)) {
delete this.onEnterFrame;
} else {
this.scale += d*this.speed;
this._xscale = this._yscale=this.scale;
}
};
};
this.onRollOver = function() {
this.zoom(1);
};
this.onRollOut = function() {
this.zoom(-1);
};
this.onClick = function() {
this.scale(100);
};
};
a.zoomInAndOut(1.5, 10);
//value of the zoom (3 will make the movieclip 3 times bigger) , speed
b.zoomInAndOut(1.5, 10);

Can someone help me modify this script?
thanks in advance