Making screen field uneditable in runtime

Question

Hi all,
   I have a field that should be READ-ONLY when the screen appears (SCREEN-INPUT = 0). Then i should be able to select F4 help for the field, for which i make     SCREEN-INPUT = 1. But after selection of a value from the F4 help i want to make the field again READ-ONLY   (SCREEN-INPUT = 0) which is not happening.
   Either am able to display the value that i select from F4 help or I am able to  make the field READ-ONLY. Both are not happening together.
   Can any one please let me know how to do this.
Thanks and Regards,
Ram.

Answer 1

hi ram kumar check this one, i worked with this kind of scenraio, check only the bold portion, the rest just shows the scenario
When i looping again at at selection screen output i check whether the field with F4 help is filled or not and then lock them accordingly
AT SELECTION-SCREEN ON VALUE-REQUEST FOR ST_NAME.
  CLEAR: FIELD_VALUE, DYNPRO_VALUES.
  REFRESH DYNPRO_VALUES.
  FIELD_VALUE-FIELDNAME = 'EXCH'.
  APPEND FIELD_VALUE TO DYNPRO_VALUES.
  CALL FUNCTION 'DYNP_VALUES_READ'
    EXPORTING
      DYNAME             = SY-CPROG
      DYNUMB             = SY-DYNNR
      TRANSLATE_TO_UPPER = 'X'
    TABLES
      DYNPFIELDS         = DYNPRO_VALUES.
  READ TABLE DYNPRO_VALUES INDEX 1 INTO FIELD_VALUE.
  IF FIELD_VALUE-FIELDVALUE IS NOT INITIAL.
    IF SY-SUBRC = 0 AND FIELD_VALUE-FIELDVALUE = 1.
      FIELD_VALUE-FIELDVALUE = 'BSE'.
    ELSEIF SY-SUBRC = 0 AND FIELD_VALUE-FIELDVALUE = 2.
      FIELD_VALUE-FIELDVALUE = 'NSE'.
    ENDIF.
    SELECT STOCK ST_NAME
                 CURRPR
                 FROM
                 ZEXCH
                 INTO TABLE TEMP_ITAB
                 WHERE EXCH = FIELD_VALUE-FIELDVALUE.
    CALL FUNCTION 'F4IF_INT_TABLE_VALUE_REQUEST'
      EXPORTING
        RETFIELD    = 'ST_NAME'
        DYNPPROG    = SY-CPROG
        DYNPNR      = SY-DYNNR
        DYNPROFIELD = 'ST_NAME'
        VALUE_ORG   = 'S'
      TABLES
        VALUE_TAB   = TEMP_ITAB
        RETURN_TAB  = RETURN.
    SELECT STOCK CURRPR
                 FROM ZEXCH
                 INTO (T_CODE, T_CURRPR)
                 WHERE ST_NAME = RETURN-FIELDVAL.
    ENDSELECT.
    CLEAR DYNPRO_VALUES[].
    FIELD_VALUE-FIELDNAME = 'ST_NAME'.
    FIELD_VALUE-FIELDVALUE = RETURN-FIELDVAL.
    APPEND  FIELD_VALUE  TO DYNPRO_VALUES .
    FIELD_VALUE-FIELDNAME = 'ST_CODE'.
    FIELD_VALUE-FIELDVALUE = T_CODE.
    APPEND  FIELD_VALUE  TO DYNPRO_VALUES .
    CALL FUNCTION 'HRCM_AMOUNT_TO_STRING_CONVERT'
      EXPORTING
        BETRG  = T_CURRPR
      IMPORTING
        STRING = T_CHAR.
    FIELD_VALUE-FIELDNAME = 'CURRPR'.
    FIELD_VALUE-FIELDVALUE = T_CHAR.
    APPEND  FIELD_VALUE  TO DYNPRO_VALUES .
* Update the dynpro values.
    CALL FUNCTION 'DYNP_VALUES_UPDATE'
      EXPORTING
        DYNAME     = SY-CPROG
        DYNUMB     = SY-DYNNR
      TABLES
        DYNPFIELDS = DYNPRO_VALUES.
  ENDIF.
*                     At  Selection-Screen output
AT SELECTION-SCREEN OUTPUT.
*  APPEND 'ONLI' TO CURRENT_SCR-EXCL.   "Execute
*  APPEND 'PRIN' TO CURRENT_SCR-EXCL.   "Execute and Print
*  APPEND 'SJOB' TO CURRENT_SCR-EXCL.   "Execute in Background
  LOOP AT SCREEN.
    IF SCREEN-NAME = 'ACCNO'.
      SELECT ACCNO
             NAME
             BANK
             BANKACC
             AMOUNT
             FROM ZUSERDETAILS
             INTO (ACCNO,NAME,BANK,BANKACC,AMOUNT)
             WHERE ACCNO = TEMP_ACCNO.
      ENDSELECT.
      SCREEN-INPUT = 0.
      MODIFY SCREEN.
    ENDIF.
    IF SCREEN-NAME = 'NAME' OR
       SCREEN-NAME = 'BANKNAME' OR
       SCREEN-NAME = 'BANKACC' OR
       SCREEN-NAME = 'AMOUNT' OR
       SCREEN-NAME = 'CURRPR' OR
       SCREEN-NAME = 'ST_CODE'.
      SELECT NAME FROM ZBANKCODE INTO BANKNAME WHERE BANK = BANK.
      ENDSELECT.
      SCREEN-INPUT = 0.
      MODIFY SCREEN.
    ENDIF.
<b>    IF SCREEN-NAME = 'ST_NAME'.
      IF ST_NAME IS NOT INITIAL AND FLAG_SEL IS INITIAL.
        CLEAR LIMPR.
        CLEAR QTY.
        IF EXCH = 1.
          L_EXCH = 'BSE'.
        ELSEIF EXCH = 2.
          L_EXCH = 'NSE'.
        ELSE.
          FLAG_END = 'X'.
          MESSAGE I000(ZZ) WITH 'Select an exchange from dropdown'.
          STOP.
        ENDIF.
        SELECT STOCK CURRPR
                     FROM
                     ZEXCH
                     INTO (ST_CODE, CURRPR)
                     WHERE ST_NAME = ST_NAME
                     AND EXCH = L_EXCH.
        ENDSELECT.
        IF SY-SUBRC <> 0.
          FLAG_END = 'X'.
          CLEAR CURRPR.
          CLEAR ST_CODE.
          CLEAR ST_NAME.
          LOOP AT SCREEN.
            IF SCREEN-NAME = 'ST_CODE' OR SCREEN-NAME = 'CURRPR'.
              SCREEN-INPUT = 0.
              MODIFY SCREEN.
            ENDIF.
          ENDLOOP.
          MESSAGE I000(ZZ) WITH 'This is not valid name of the stock'.
          STOP.
        ENDIF.
      ENDIF.</b>
    ENDIF.
  ENDLOOP.