Making form field elements invisible when printing

Hello,

Is it possible to make a form field element invisible when printing?  For example, I made a form field for entering an invoice contact name, but I added a field element that says: "enter only if different from main contact"  (see image below) I don't really want that sentence to print if the field isn't filled out.

Is this possible?

Image may be NSFW.
Clik here to view.

Thanks,

Emily