Show navigation items as completed...

Hello,

Being a newbie to Story line I am having trouble with a variable based trigger. I seem to remember having seen a post regarding this earlier, but I simply can´t find it.

Here is the problem:

I have a course of 5 scenes. Each scene is referred to on a lightbox navigation slide that the learners can refer to at will. What I would like do is having the items on the lightbox  navigation slide to show up as "completed", after the relevant scene is completed.

What I have done is to make a true/false variable "Scene completed", defaulted to "false". On the last slide in the scene I have set the variable to change to "true" after slide timeline ends. On the navigation slide I have a "Completed" state of the specific object with a trigger to change to the completed state when the specific variable for the scene changes to "true". Somehow this does not work....

Any suggestions?