Referencing a movieclip within an attached movieclip

Hello,
I am trying to reference a movieclip within a movieclip that I am loading using “attachmovie”. In the first frame of the root, I am attaching the movie. Then, from the attached movie I am calling a function that is also in the first frame of the root.
In the function I am tring to set the property of a clip within the attached movie to visible using the following code:

_root.logIn.loginMessage._visible = true;

I have also tried _root[“logIn”].loginMessage._visible = true; with no luck.

(logIn is the name of the clip I am attaching using attachMovie and loginMessage is the clip I am trying to reference in the attached movie)

This is how I’m loading it and I know that part is working:
_root.attachMovie(“login_mc”,“logIn”,getNextHighestDepth());

Any suggestions?