Why doesnt it play?!

    if(Key.isDown(_root.ATTACKRIGHTKEY)){
        if(_root.mcPLAYER.GROUNDED == true) {
            if (_root.mcPLAYER.DIRECTION == "R") {
                _root.mcPLAYER.gotoAndStop(12)
            }
        }
    }

when i do press cntrl(ATTACKRIGHTKEY) frame 12 doesnt play what is in it it just stops on the first frame of the animation

this happens to me a lot i have no idea why any ideas?