Split large flash file into smaller ones

Hi,
I have a flash file (website) that has become very large. So far I have several frame with different names and I use them to navigate trough the site.
example of a navigation button:

on(release){
with(_root){
gotoAndPlay(“portfolio”);}
}

I want to split this file into smaller ones, probably one per page.
I know how to create n files.
But then how do I navigate through them? How do I link them?

I hope my question is clear.
Thanks
alessandra