Hey, I need help removing movieClips using AS2 when you switch to the next level. I'm having trouble doing it.

Heres the code below:
Actionscript Code:
_root.attachMovie("ball", "ball", _root.getNextHighestDepth(), {_x:30, _y:30});
_root.attachMovie("wall3", "wall3", _root.getNextHighestDepth(), {_x:260, _y:200});
_root.attachMovie("end","end", _root.getNextHighestDepth(), {_x:230, _y:200});
_root.attachMovie("arrow", "arrow", _root.getNextHighestDepth());
moving = false;
gravity = 0.01;
xspeed = 0;
yspeed = 0;
precision = 24;
radius = 15;
Mouse.hide();
arrow.onEnterFrame = function() {
    this._x = _xmouse;
    this._y = _ymouse;
    dist_x = ball._x-this._x;
    dist_y = ball._y-this._y;
    total_dist = Math.sqrt(dist_x*dist_x+dist_y*dist_y);
    if (total_dist>300) {
        total_dist = 300;
    }
    total_dist = (300-total_dist)/500;
    angle = Math.atan2(dist_y, dist_x);
    this._rotation = angle*57.2957795;
};
ball.onEnterFrame = function() {
    if (moving) {
        dir = arrow._rotation;
        xspeed += total_dist*Math.cos(dir*0.0174532925);
        yspeed += total_dist*Math.sin(dir*0.0174532925);
    }
    yspeed += gravity;
    this._x += xspeed;
    this._y += yspeed;
    xspeed *= 0.99;
    yspeed *= 0.99;
    for (x=1; x<precision; x++) {
        spot_x = this._x+radius*Math.sin(x*360/precision*0.0174532925);
        spot_y = this._y-radius*Math.cos(x*360/precision*0.0174532925);
        if (wall3.hitTest(spot_x, spot_y, true)) {
            xspeed = 0;
            yspeed = 0;
            this._x = 30;
            this._y = 30
            0;
        }else{
            if(end.hitTest(spot_x, spot_y, true)){
             _root.gotoAndStop(8)
              _root.removeMovieClip.wall2
        }
    }
};
}
_root.onMouseDown = function() {
    moving = true;
};
_root.onMouseUp = function() {
    moving = false;
};