Now and then, it is desirable to display values in fields on a window even though the values are not stored in the LU connected to the window. An example: in the LU for orders, the customer ID is stored. However, on a window displaying orders not only the customer ID, but also the customer name should be displayed. This would not be stored in the same LU, but should be fetched from the Customer LU. Each time the customer ID on the order window is changed, the displayed customer name must be updated. This is automated by making the customer ID field the logical parent of the customer name field.
To make one field update depending on another field: