This screen is where a customer invoice is created. It includes the customer information, products bought, prices, subtotals, tax, and total amount due. As you will see when the input processing (programming) for this screen is discussed, much of the above information is calculated and filled in automatically, saving the data-entry operator much time and avoiding errors. Here is what the finished screen looks like in Define Screens:
Figure 21 - 1. Invoice File Data—Entry Screen (in Define Screens)
The “*“ and “!“ symbols, you may recall, are field indicators. They indicate the exact position of the beginning of the field. They also indicate whether a field can be modified by the user or not:
* means the user can modify the field contents.
! means that the field is protected; the user cannot modify it.
The protected fields will be automatically filled in with information from other files or with the results of mathematical calculations.