Advance to next slide

Hi all,

Thank you all. Now I know how to restrict the next or pre button. But I'm still a bit confused about how to remain the Next Button normal when revisiting the slide.

For example, I set when the timeline reaches 5s, the state of Next Button to Normal in slide 1.6 BD Document Handling Procedure.  When the timeline reaches 5s, I can click the Next Button to slide 1.7. When I go back to slide 1.6, I need to wait for 5s again to get the normal state of Next Button. So how to set a trigger or variable so that when I revisit this slide, the Next Button remains normal and do not need to wait for 5s again? 

The other one is that...in the result slide, I set learner can retry the quiz once. When I click retry button, it goes to the question slide successfully. But when I submit the Q1 and click next, it goes to the next slide rather than Q2 question slide directly. Is there any way to only go through Qs slides when I retry the quiz