Simply use the MsgBox Function
MsgBox(prompt[, buttons] [, title] [, helpfile, context])
where the 2ns input variable specifies which button whouls appear to the
user. In your case you'd want vbYesNo or vbOKCancel.
Look it up in the help file, it has an example that even shows you how to
get the users choice to then move forward with your code.