Movie clip inside of a movieclip problems

I’m trying to follow this tutorial for scrolling images and I got it to work successfully. But I wanted to put it inside another movie clip, problem is as soon as I do that it dosnt work.

I think it has something. The onyl piece of code I can find that I think would be affected by this change is this.

mc = _root.drag._x
mp = _root.drag._y

but I’ve changed it to

mc = _root.content_mc.drag._x
mp = _root.content_mc.drag._y

and its still dosnt work. are theyre any other factor I should be looking for.