Can I have a form that when it is submtted a pop up is shown?

What we want is for after the user pays the regular price for our class and hits submit for a pop up box to come up that says hey if we do get this class full and thus can offer a lower price what do you want to happen to your money?  Do you want to get the money back or make it a donation to our cause?  Then they would hit submit and the Thank you screen would come up.

Is that possible?

You can use Custom Thank you page to accomplish that, so when your customers submit the form they will be redirected to that Custom page so they can continue with the process.

The workflow would be, your customer submits the form, they are redirected to another form where they choose if they will do the donation or not.

Another way would be to do some coding, my colleague made a guide in this thread. Where when you click the submit button a pop up should show.

Hope this information helps.

Let us know if you have further questions.

Thank you!