Using fold_page_list and want to highlight selected tab

Thi8s should be easy, but I can’t seem to get it right…

I am using fold_page_list for my menu and it works great, does exactly what I want, however, I want to make the selected tab look different, just like this site is doing. I looked at the source for this site and I see that the class is changed to ‘current’ for the menu item of the selected page, is that done with javascript?

I would like to implement this while using fold_page_list, is that possible?

Thanks!