Using a disclaimer in excel
 

I have figured out the userform to create a disclaimer and it pops up when I
open the workbook but how do I get the work book to open/close according to
the selection they make. Right now it only closes via the cross, and the
option buttons in the user form don't do anything.

The code i am using to get the userform to come up is:
Private Sub Workbook_Open()
Application.ScreenUpdating = True
PopQuiz.Show
Application.ScreenUpdating = False
End Sub

Answers in laymens terms please as i am a beginner!!

Thanks