INPUT Statement Control blocks

Control blocks BEFORE FIELD and ON CHANGE are called automatically during an INPUT as the user moves the cursor through the fields of a form.

For example:

• BEFORE FIELD control blocks are executed immediately prior to the focus moving to the specified field. The example program uses this control block to prevent the user from changing the store number during an Update, by immediately moving the focus to the store name field (the NEXT FIELD instruction).
• An ON CHANGE is used to verify the uniqueness of the store number that was entered, and to make sure that the store name is not left blank. The user receives notification of a problem with the value of a field as soon as the field is exited. Validating these values as they are completed is less disruptive than notifying the user of several problems after the entire record has been entered.

See INPUT control blocks in the Genero Business Development Language User Guide for a complete list of INPUT control blocks.