How do I create a message box that only appears from some pages

How could you create a message box that only appears when a user is running a macro from a specific page.

For example, I have a navigation bar for a model that runs the side of each worksheet with macro buttons that allow movement between pages. When a user moves from the first page "Directions" to the second "General" I want an error box to appear encouraging the user to read the directions before moving on. However, I do not want this same message box to appear as the user goes from say, page three "Inputs" to page two "General".

Any help is greatly appreciated.

This is what I have right now:

If MsgBox("Are you sure you want to delete Column G? Data will be unrecoverable!", vbYesNo) = vbNo Then Exit Sub