I would like to know how you can keep running a function over and over again, so that it can keep adding the stored value. For example If Bob uses a program to purchase a ticket, lets say that Bob purchases 5 tickets out of 55 tickets (There's only 55 seats).So, now there is only 50 tickets left. Alice, comes and uses the program to purchase another 5 tickets. This will minus from the current value which is 50 and this will continue to happen until there's no tickets left and the program gives out an error message. How can I keep looping the function over and over again, so that different people can come and purchase any amount of tickets and then the program will take the quantity of the tickets and minus it from how many tickets there are left.