can tabs/buttons on master pages utilize variables to change state?

Hi

I have a section that requires navigation tabs so I'm putting them on a master page. I need to force the user through a linear progression of the content, and thus not make all the tabs active until they have first completed the section before it. Once they have completed each tab, I want them to be able to click around and move freely between the viewed tabs, should they choose to do so.

So, I have the tab's default view set to "disabled" on the master page.

I have global variables for each tab section that set the "completed" value to FALSE.

I was thinking that as the user progressed through the course, I'd have each specific "completed" variable change to TRUE once use clicks the "next" button while in that section, thus triggering the trigger I have set on the master page that changes the tab from "disabled" to "normal" once "completed" equals TRUE.

This doesn't appear to be working though. Even as I click "next" and progress through the tabs, they always remain "disabled."  Do the variables not "speak" to the master page triggers?

Each of the tabs has a lot going on within it, utilizing slide layers, so that's why I'm using a master page for the main tab navigation.

Attached is a sample file to help clarify.

Thanks for your help.

Karen