Getting correct x & y coordinates

When I make a MC and I put another MC inside of it, whenever I write code in the frame of the main stage to use the child MC’s x and y coordinates, I get the child MC’s coordinates in respect to the _parent MC. If what I wrote didnt make any sense, what I mean is that if I make a tank MC named tankBody and a turret MC named tankTurret, and I stick them both in a MC called tank, if I write code that moves the tank MC’s y the tankTurret and tankBody’s y will stay the same. How can I make it so that I can read tankTurret’s y & x coordinates in repect to the main stage?