Casio V-REGI Series Reference Manual page 74

 If the customer is already selected on the sales registration screen, it is not need
to select customer again.
 After select customer, History of Customer Accounts will appear on the screen.
 Tap <Payment>, Dialog of input amount will appear to input amount of
payment.
 After input the amount of payment, tap <OK> on the dialog.
 Register to sales management system as payment of customer charge.
 After register it, the operation of finalize transaction is same as normally one.
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