puoi fare così

tasto +
codice:
on (press) {
	map.onEnterFrame = function(){
		if (this._xscale<500) {//max ingrandimento
		this._yscale +=5;
		this._xscale +=5
    			}else{
		delete map.onEnterFrame;
			}
		}
}
on(release){
     delete map.onEnterFrame;
}
tasto -
codice:
on (press) {
	map.onEnterFrame = function(){
		if (this._xscale>200) {
		this._yscale -=5;
		this._xscale -=5
    			}else{
		delete map.onEnterFrame;
			}
		}
}
on(release){
     delete map.onEnterFrame;
}
fammi sapere se ti va bene