Previous Slide Trigger

I have used buttons for next/previous links instead of using the default ones on the player. I have placed them on the master slide and applied the previous/next triggers to them. They function correctly when using just the buttons to navegate the lessons.

Here's the problem. When you select a slide from the menu, then click previous slide it doesn't go to the previous slide in numbered order it goes to the slide you were just on.

So, to break it down say you were clicking next until you're on page 5, then go to the menu and skip to slide 10, then click the previous button, you don't go to slide 9, you go back to slide 5. I don't want it to do this. Is there a way to stop it from functioning this way besides changing the next/previous buttons to go specifically to a slide. I only ask this because slide structure/layout design can change after you have created it and I don't want to have to go through and keep manually changing the buttons. I'd like to be able to do it from the master.