PROCESS BEFORE OUTPUT.
MODULE init_screen_0100.

PROCESS AFTER INPUT.


MODULE CANCEL AT EXIT-COMMAND.
MODULE DO_.

MODULE CANCEL INPUT.
  LEAVE PROGRAM.
ENDMODULE.

MODULE DO_ INPUT.
  CASE sy-ucomm.
    WHEN 'CANCEL'.
      LEAVE PROGRAM.
      ENDCASE.
    When .....
ENDMODULE.