Variable referencing (should be easy)

Hi,

This is easy but I am having issues.

I have two movieclips, Movieclip1 and Movieclip2.

Movieclip2 has a variable called variable2.

How can I reference variable2 that is in movieclip2 from movieclip1

I thought it would be _root.movieclip2(variable2)

but I am apparently wrong, How do u do it?