user scans the prices of the item, which will be added to the price line item, after scanning all the items, user sums up the sub total and asks from the customer method of payment.if the customer wishs to pay be cash, customer gives the money (either amount is larger than the sub total or exact amount) which ever it is, after customer hands over the money to user, he will enter the money he recieved from the customer to the system, then system calculate the balance (if the amount is larger than the sub total) and sends the signal to cash drawer to open it with the balance user must give back to the customer on the screen, user put the amount he received from customer to the drawer and gets the change and close the drawer.
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