[Raist]

Можно примитивно:

var size : Number = 24;

this.gotoAndStop(3);

this.onRollOver = function () {
size = 32;
}

this.onRollOut = function () {
size = 24;
}

this.onPress = function () {
this.gotoAndStop(2);
}

this.onMouseUp = function () {
this.gotoAndStop(3);
}

this.onEnterFrame = function () {
if (this._height < size) {
this._width += 3.2;
this._height += 2;
if (this._height > size) {
this._width = size * 1.6;
this._height = size;
}
}

if (this._height > size) {
this._width -= 3.2;
this._height -= 2;
if (this._height < size) {
this._width = 40;
this._height = 24;
}
}
}