Issue creating a "go back" button in flash

Hello Everyone,
Im having an issue with a site im creating, i have everthing broken down and put to work but one single thing.

on the site with 3 buttons and there are 3 sections for each button.
1 is the home page
2 is the media page (portfolio)
3 is the contact page

in my portfolio page i have a submenu that has sub portfolio pages that i created on diferent swf files and i have them load on a empty movie clip with the A.S code “LoadMovieNum” on diferent Frames and diferent levels.

my issue is that everytime i go to one the sub pages, it erases all the content (even the submenu) from the previous sub pages and i dont know how to create a “go back” button that goes back to the main part of the media page, or some sort of code that doesnt remove all of the content just what was loaded previously.

thank you in advance i hope my details are accurate,

Angel