MC WithIn An MC Rotation

programming flash
1

I have this code to make tank barrels rotate to mouse possition and It works
If I use just the barrels.
But when I put the berrals MC In the tank MC (on top of tank) the code doesn’t work.
Her’s the code

_root.onEnterFrame=function(){
xd=_root._xmouse-_root.Barrel7._x;
yd=_root._ymouse-_root.Barrel7._y;
rot=Math.atan2(yd,xd);
toRad=180/Math.PI;
rot*=toRad;
_root.Barrel7._rotation = rot;
}

I tried another code for the barrels on the tank but It acts wierd.

I Included the fla file If anyone can help.
There’s one barrel on stage working good and one barrel on the tank thats not.
Thanks.