AS2 CODE:
var dir:Number = 1
this.onEnterFrame = function () {
this.gotoAndStop(this._currentframe + this.dir)
if (this._currentframe == this._totalframes){
this.dir = -1
} else if (this._currentframe == 1){
this.dir = 1
}
}
AS3 CODE:
var dir:int = 1
addEventListener(Event.ENTER_FRAME, animate)
function animate (evt:Event) {
gotoAndStop(currentFrame + dir)
if (currentFrame == totalFrames){
dir = -1
} else if (currentFrame == 1){
dir = 1
}
}