About current frame property

Hello I am trying to make as3 take action when a certain frame is reached. As far as I understand I need to use current frame property. But it does not work for some reason. It is about as. file so my object is referred to as "this". 

if (this.hitTestObject(_root.mcBall)){

    _root.ballYSpeed *= -1

    if(!hit){      

        hit = true

        this.gotoAndStop(2)

    } else {      

        this.gotoAndStop(3)

  removeEventListener(Event.ENTER_FRAME, enterFrameEvents);

_root.brickAmt --;

I have animation playing inside frame 3 at the end of which goes to (parent) frame 4. How can I tell it if the current frame is 4 to do  _root.brickAmt --;  At this point? Is there another command I can use?

Thanks!