import flash.events.Event; addEventListener(Event.ENTER_FRAME,_enter); var _flag:Boolean=true; function _enter(e:Event):void { if (_flag) { _rect.alpha+=(0-_rect.alpha)*0.2; if (_rect.alpha<0.05) { _rect.alpha=0; _flag=false; } } else { _rect.alpha+=(1-_rect.alpha)*0.2; if (_rect.alpha>0.98) { _rect.alpha=1; _flag=true; } } }