Can I limit the use of the form?

I have two forms. One for membership submission and one for registration with payments. I would like to give a discount on the registration  for al all members  

The question on this post appears to be incomplete. I see that you have posted a more complete version of your concern on another thread. Since that thread has more details, we shall answer your question there. Please follow this link to view that thread: https://www.jotform.com/answers/872557. Thank you.