IDENTIFICATION DIVISION.
PROGRAM-ID. EXAMPLE-SCREEN-PROGRAM.
ENVIRONMENT DIVISION.
CONFIGURATION SECTION.
   SOURCE-COMPUTER. T16.
   OBJECT-COMPUTER. T16,
   TERMINAL IS T16-6520.
SPECIAL-NAMES.
   F1-KEY IS F1, F2-KEY IS F2, F15-KEY IS F15, F16-KEY IS F16
   SF1-KEY IS SF1, SF16-KEY IS SF16, ATTENTION IS REVERSE.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 WS.
   02 ERROR-MSG PIC X(64).
01 EXIT-FLAG PIC 9 VALUE 0.
   88 EXIT-PROGRAM VALUE 1.
01 SEND-ERROR-FLAG PIC 99.
01 ENTRY-MSG.
   02 PW-HEADER.
      04 REPLY-CODE PIC S9(4) COMP.
      04 FUNCTION-CODE PIC XX.
         02 MESSAGE-NUMBER PIC 9.
01 ENTRY-REPLY.
   02 PW-HEADER.
      04 REPLY-CODE PIC S9(4) COMP.
      04 FILLER PIC X(2).
   02 SERVER-RECORD PIC X(64).
01 ERROR-REPLY.
   02 REPLY-CODE PIC 9(4) COMP.
   02 FILLER PIC X(2).
   02 ERROR-CODE PIC 999 COMP.
SCREEN SECTION.
01 EXAMPLE-SCREEN BASE SIZE 24, 80.
   03 FILLER				AT 1, 20	VALUE "EXAMPLE SCREEN COBOL PROGRAM".
   03 FILLER				AT 10, 1	VALUE "MESSAGE NUMBER :".
   03 MESSAGE-NUMBER 			AT 10, * + 2 	PIC 9, 
							USING MESSAGE-NUMBER OF ENTRY-MSG.
   03 MESSAGE-TEXT	AT 12, 1	PIC X(64) 	FROM SERVER-RECORD OF ENTRY-REPLY.
   03 FILLER				AT 21, 15 	VALUE "F1 - READ F16 - EXIT PROGRAM".
   03 ERROR-MSG		AT 24, 2	PIC X(64) 	ADVISORY FROM ERROR-MSG OF WS.
PROCEDURE DIVISION.
A-MAIN.
   DISPLAY BASE EXAMPLE-SCREEN.
   MOVE 0 TO MESSAGE-NUMBER OF ENTRY-MSG.
   DISPLAY MESSAGE-NUMBER OF EXAMPLE-SCREEN.
   PERFORM CASE-MANAGER UNTIL EXIT-PROGRAM.
A-EXIT.
   EXIT PROGRAM.
CASE-MANAGER.
   ACCEPT MESSAGE-NUMBER OF EXAMPLE-SCREEN 
    UNTIL F1-KEY ESCAPE ON F16-KEY (F2-KEY THROUGH F15-KEY, SF1-KEY THROUGH SF16-KEY).
   PERFORM ONE OF READ-MESSAGE, 
		  SET-EXIT, 
		  KEY-NOT-SUPPORTED
		  DEPENDING ON TERMINATION-STATUS.
READ-MESSAGE.
   MOVE "01" TO FUNCTION-CODE OF ENTRY-MSG.
   PERFORM SEND-DATA.
SET-EXIT.
   MOVE 1 TO EXIT-FLAG.
KEY-NOT-SUPPORTED.
   MOVE "FUNCTION KEY NOT SUPPORTED" TO ERROR-MSG OF WS.
   PERFORM DISPLAY-ADVISORY.
SEND-DATA.
   MOVE 0 TO SEND-ERROR-FLAG.
   SEND ENTRY-MSG TO "EXAMPLE-SERVER"
	REPLY CODE 0   YIELDS ENTRY-REPLY
	      CODE 999 YIELDS ERROR-REPLY ON ERROR PERFORM
SEND-ERROR.
  IF SEND-ERROR-FLAG = 99
     DISPLAY TEMP "SEND ERROR" IN ERROR-MSG OF EXAMPLE-SCREEN   
   ELSE 
     PERFORM ONE OF PARA-1 PARA-2 DEPENDING ON TERMINATION-STATUS.
PARA-1.
   MOVE SPACES TO ERROR-MSG OF WS
   DISPLAY MESSAGE-TEXT OF EXAMPLE-SCREEN, ERROR-MSG OF EXAMPLE-SCREEN.
PARA-2.
   PERFORM SETUP-SERVER-ERROR
   PERFORM DISPLAY-ADVISORY.
SEND-ERROR.
   MOVE 99 TO SEND-ERROR-FLAG.
SETUP-SERVER-ERROR.
   IF ERROR-CODE = 1

			MOVE "SERVER FUNCTION NOT SUPPORTED" TO ERROR-MSG OF WS
		ELSE
		IF ERROR-CODE = 2
			MOVE "MESSAGE DOES NOT EXIST FOR SPECIFIED NUMBER" TO ERROR-MSG OF WS
		ELSE
			MOVE "UNKNOWN SERVER ERROR" TO ERROR-MSG OF WS.
DISPLAY-ADVISORY.
		DISPLAY TEMP ERROR-MSG OF EXAMPLE-SCREEN.
		TURN TEMP ATTENTION IN ERROR-MSG OF EXAMPLE-SCREEN.