I have a form in my PHP file for students registration that have four inputs name, ID, email and time slot (this have options of 4 time slots and in each slot 8 seats remaining). I don't want store data in database. My purpose is that when a student put info in fields and select one time slot and proceed by clicking on submit button then next time the same slot shows seat subtracted i.e if it was 8 now it will shows 7 and after 7 submission it will show no seats or 0 seats. I want to apply this method on 4 slot (option) in this input fields.