modify statement is not working with internal table

[Balu483]

in table control i want to modify table control internal table after user PRESS ENTER  .

but internal table is not getting modified it is giving sy-subrc = 4.

please help me how to modify internal table and display the data in table control in module pool program

my logic:

FLOW LOGIC:

PROCESS BEFORE OUTPUT.

MODULE status_0483."""for pf status

  LOOP AT gt_fdint INTO gs_fdint WITH CONTROL tab_con CURSOR

                                        tab_con-current_line.

  ENDLOOP.

PROCESS AFTER INPUT.

  LOOP AT gt_fdint .

    CHAIN.

      FIELD gs_fdint-zselno.

      FIELD gs_fdint-zcustm.

      FIELD gs_fdint-zfddes.

      FIELD gs_fdint-zstart.

      FIELD gs_fdint-zenddt.

      FIELD gs_fdint-zaccrl.

      FIELD gs_fdint-zintrs.

      FIELD gs_fdint-zintdes.

      FIELD gs_fdint-zpstdt.

      FIELD gs_fdint-channel.

      MODULE tc_acunt_modify ON CHAIN-REQUEST.

    ENDCHAIN.

  ENDLOOP.

  MODULE user_command_0483."""USER COMMAND SUBROUTINE

  MODULE exit_command_483."""EXIT COMMAND SUBROUTINE

MODULE tc_acunt_modify INPUT.

  MODIFY gt_fdint

         FROM gs_fdint

         INDEX tab_con-current_line.

ENDMODULE.

hear internal table is initially contains no record, if  i give sone input in table control and press enter then

MODULE tc_acunt_modify ON CHAIN-REQUEST. is triggering and but it is not modifying the internal table 

after MODIFY statement it is giving SY-SUBRC = 4.

[Former Member]

Hi,

first insert a initial line in the internal table and then modify the same as below.

PROCESS AFTER INPUT.

  LOOP AT gt_fdint .

    CHAIN.

      FIELD gs_fdint-zselno.

      FIELD gs_fdint-zcustm.

      FIELD gs_fdint-zfddes.

      FIELD gs_fdint-zstart.

      FIELD gs_fdint-zenddt.

      FIELD gs_fdint-zaccrl.

      FIELD gs_fdint-zintrs.

      FIELD gs_fdint-zintdes.

      FIELD gs_fdint-zpstdt.

      FIELD gs_fdint-channel.

      Module tc_insert_line ON CHAIN-REQUEST.

      MODULE tc_acunt_modify ON CHAIN-REQUEST.

    ENDCHAIN.

  ENDLOOP.

  MODULE user_command_0483."""USER COMMAND SUBROUTINE

  MODULE exit_command_483."""EXIT COMMAND SUBROUTINE

MODULE tc_insert_line INPUT.

  READ TABLE  gt_fdint INDEX tab_con-current_line TRANSPORTING NO FIELDS.

  IF sy-subrc <> 0.

    INSERT INITIAL LINE INTO  gt_fdint INDEX tab_con-current_line.

  ENDIF.

ENDMODULE.                 " tc_insert_line  INPUT

MODULE tc_acunt_modify INPUT.

  MODIFY gt_fdint

         FROM gs_fdint

         INDEX tab_con-current_line.

ENDMODULE.

Hope this helps.

[VenkatRamesh_V]

Hi Chandu,

Modify statement never insert  a new record in internal table.

  MODIFY gt_fdint

         FROM gs_fdint

         INDEX tab_con-current_line.

IF sy-subrc <> 0.

INSERT gs_fdint INTO gt_fdint    INDEX tab_con-current_line.

ENDIF.

Hope it helpful,

Regards,

Venkat.

[Balu483]

Hi Venkat Ramesh,

thank you so much for your reply . really it is so helpful.

[Former Member]

Create your table control using the table control wizard rather than doing it be hand.

Rich