I am creating a userform with questions that has Yes/No answers.
How do I write a script that activate a window or popup only when the answer is "Yes".
Eg: Do you have a case number? Yes/No. As soon as you select Yes from the drop down list, a dialog box, or pop up or something comes up that allows you to fill in the number; OR another drop down list to select number range. Hope this makes sense. Help!

That really depends on what the element names of the userform are and how you want the pop-up activated. You could also conditionally show/hide the relevant textbox/dropdown on the userform itself.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]

One additional possibility would be to conditionally insert/display AutoText entries.