When a form has conditional fields, the registrant is allowed still to proceed to the payment page before the conditional fields appear. This is the case even if some conditional fields are required. I've put a note above the fields telling registrants to wait for the conditional fields to appear (understanding that this will necessarily take time for slow connections), but occasionally you still get someone that clicks through without seeing important fields. It would be great if this didn't have to be the case!
Similarly, I would like to have the ability to pause/hold/halt the user from registering further if one of the required fields is not selected to a proper value. For instance, if a user is presented with:
"Are you an [A] or a ?"
If they choose , then a textual prompt says "You cannot be at this event!!! Choose [A] instead." and holds them there until [A] is selected. Once [A] is selected, the "Next" button appears or can appear if the other required fields are filled.