While you are viewing the CustomShow by default you can navigate through the slides in CustomShow by clicking on the right or left part of the slide. 

When you click right part of the slide, you will be navigated to the next slide and if you click the left side you will be directed to the previous slide. 

If you have buttons or links in your CustomShow for navigation, you can disable this default presentation navigation.

Check the steps below to disable the default presentation navigation.