How to force the focus by program, to move or stay in a specific form element.
Use the NEXT FIELD instruction to force the focus to a specific field or screen record (list). The NEXT FIELD instruction expects a form field name.
DIALOG ATTRIBUTES(UNBUFFERED)
   INPUT BY NAME p_cust ATTRIBUTES(NAME="cust")
     ...
   END DISPLAY
   DISPLAY ARRAY p_orders TO orders.*
     ...
   END DISPLAY
   ON ACTION go_to_header 
      NEXT FIELD cust_num 
   ON ACTION go_to_detail 
      NEXT FIELD order_lineno 
   ...
END DIALOG
DIALOG ATTRIBUTES(UNBUFFERED)
   ...
   COMMAND "print" 
      CALL print_order()
   ...
END DIALOG
DEFINE form ui.Form
...
DIALOG ATTRIBUTES(UNBUFFERED)
   ...
   BEFORE DIALOG
      LET form = DIALOG.getForm()
   ...
   ON ACTION show_image1 
      CALL form.ensureElementVisible("image1")
   ...
END DIALOG