Application.SlideShowOnPrevious Event (PowerPoint)
Occurs when the user clicks Previous to move within the current slide.
To access Application object events, declare a variable to represent the Application object in the General Declarations section of your code. Then set the variable equal to the Application object for which you want to access events. For more information about using events with the Microsoft PowerPoint Application object, see How to: Use Events with the Application Object.
The SlideShowOnPrevious event does not fire when users click Previous to move from one slide to the previous one, but rather only when they click Previous to move within a given slide, for example to rerun the previous animation on the slide.
This example displays a message every time a user clicks Previous to move with the current slide. The example assumes that you have already declared an Application object named App in the General Declarations section of your code, using the WithEvents keyword.