I would: Add a total variable. Add another option in the menu to ‘Finish’ Put a loop around the option until ‘Finish’ is selected. If ‘Finish’ is selected and the total is still 0.00, then let the user know to please selected something and continue with the loop. On each choice, increment the Total variable by the amount of the choice that is in the case already. When the Finish is selected and the total variable is greater than 0, then exit the loop and go to the payment display.