Scale swf whithout scaling loaded movies?

Hello… How can I resize a flash movie without resizing the loaded movies that I have in it?
I mean… I have a main scalable swf (“movie A”), that contanis another movie (“movie B”) whith an specific size. I need to resize “Movie A” when I resize the browser window, and keep “movie B” same size.

I need to center “Movie B” automatically inside “Movie A” also…

Could anyone help me whith that?
Thanks in advance!