BEFORE CONSTRUCT block

The BEFORE CONSTRUCT block is executed once at dialog startup, before the runtime system gives control to the user for criteria input. This block can be used to display messages to the user, initialize form fields with default search criteria values, and setup the dialog instance by deactivating unused fields or actions the user is not allowed to execute.

CONSTRUCT BY NAME where_part ON ...
   BEFORE CONSTRUCT
       MESSAGE "Enter customer search filter"
       CALL DIALOG.setActionActive("clean", FALSE )
   ...

The fields are cleared before the BEFORE CONSTRUCT block is executed.

You can use the NEXT FIELD control instruction in the BEFORE CONSTRUCT block, to jump to a specific field when the dialog starts.