Display Pop-Up in PDF when Clicked or Typed?

I have a collection of example documents in PDF forms that are viewed by clients, They all include a "Example" watermark prominently displayed but I have had some issues with clients trying to fill in the example forms and submitting as Official forms, normally followed by a support phone call from the client. I am looking for a way to pop up a message in the pdf if the client trys to t开发者_JAVA技巧ype or click in the example document, I know how to pop up a message if they click in a form field but some of my documents do not have any form fields so I am looking for a way to show a message if a client trys to type or click anywhere in the actual document. I am using Acrobat X Pro.

Does anyone know of a way to do this?

Thanks in advance for any advice!!

Plop a big invisible button (not hidden, invisible) over the entire page, with a click action that pops up a message dialog with whatever warning you wish.