Filename disappears on selection screen -BDC

Question

Hi all,
I have an issue with my BDC,the seleection screen for picking up the file using parameters doesnt comes up in my parameter box. following is the code i'm using :
DATA: g_filename TYPE string.
**************FILE UPLOADING/DOWNLOADING**************************************
SELECTION-SCREEN BEGIN OF  BLOCK block WITH FRAME TITLE text-001.
PARAMETERS : in_file LIKE rlgrap-filename OBLIGATORY.
            SUC_FILE LIKE RLGRAP-FILENAME OBLIGATORY,
            SUCI_FIL LIKE RLGRAP-FILENAME OBLIGATORY,
            ERR_FILE LIKE RLGRAP-FILENAME OBLIGATORY.
SELECTION-SCREEN END OF BLOCK block.
For Browsing the Input File Name on the Presentation Server         *
AT SELECTION-SCREEN ON VALUE-REQUEST FOR in_file.
CALL FUNCTION 'C13G0_GET_FILENAME_F4'
    CHANGING
      x_filename    = in_file
    EXCEPTIONS
      mask_too_long = 1.
PERFORM get_filename USING in_file.
Using call function for uploading a file                             *
START-OF-SELECTION.
g_filename = in_file.
  CALL FUNCTION 'GUI_UPLOAD'
    EXPORTING
      filename            = g_filename
      filetype            = 'ASC'
      has_field_separator = 'X'
    TABLES
      data_tab            = it_bdc.
END-OF-SELECTION.
NEED HELP GURUS !
EAGERLY WAITIN FOR REPLIES,
SACHIN

Answer 1

i guess the FM u had used should contain one more exporting parameter,
but use his
AT SELECTION-SCREEN ON VALUE-REQUEST FOR in_file.
  CALL FUNCTION 'F4_FILENAME'
       EXPORTING
            program_name  = v_repid
            dynpro_number = syst-dynnr
            field_name    = 'IN_FILE'
       IMPORTING
            file_name     = in_file.