I'm trying to create an alphabetical menu for my database of interviews. I'm using repeaters and it's working fine--except for one thing. See my screenshot below: we're on page E, displaying all interviewees with last names beginning with 'E', we got there by pressing the 'E' button circled in the navigation. But now that we're on this page (which is a dynamic collection page), I want the 'E' button to be disabled (and then reenabled if I click on a different letter). How can I do that please? (And many thanks for your great service).