Is it possible to update the number or spots available on my form?

I am trying to make my form able to show how many spots i have available for a training program i run. sometimes the number of spots changes and sometimes people cancel. How can I update the number or spots available on my form to reflect this change after someone has book a training class with me?

We have Appointment slots widget that might help you to achieve your requirement. 

https://widgets.jotform.com/widget/appointment_slots

This widget allows editing the slot by editing the submission and change the slots by updating the widget from the build mode.

Could you give it a try and check if that works for you?

Please get back to us if you need any further assistance. We will be happy to help.