How to successfully carry variables across multiple slides?

Hi,

I am new to Articulate and I come as a designer (program knowledge is limited). Everything is going fine, I have video, pictures, text etc in my project but one thing I can't seem to fathom is variables. I have read a lot about variables being able to carry their state across multiple slides but I can't seem to achieve it.

My goal is to have a user recognise by coloured markers as to which pages have been fully viewed and which haven't. I am using oval vectors and want to change their state from hidden to normal when the timeline ends for each slide. This is relatively easy as I just drop a trigger in asking Articulate to do it. What I can't seem to do is carry that variables state over to the next slide. Say a user moves on to the next slide and then decide to go back to the previous slide the vector will always remain hidden even after the timeline ends.... so annoying!

If anyone can help or has had similar problems I would love to know how to do it as I can't seem to get around it.

Many Thanks,

-Aly