Dump in f4 help

Question

I have developed one program to download spool job for that i have taking sppol number and file name in selection screen . In the seelction screen for file name i have kept f4 for filename it is working fine but if i did not give the extension it is going to dump .
The dump message is " The program attempted to issue a " " message during "F4" processing. This is an illegal operation. How to correct this pls let me know any one .
my code is
REPORT  ZSD_SPOOL_DOWNLOAD.
TABLES:tsp01.
SELECTION-SCREEN  BEGIN OF BLOCK b1 WITH FRAME TITLE text-001.
  PARAMETERS: SPOOLID LIKE  TSP01-RQIDENT.
             p_fname LIKE  IBIPPARMS-PATH .
  PARAMETERS p_file      TYPE dxfile-filename.
SELECTION-SCREEN end of block b1.
DATA:P_fname1 LIKE RLGRAP-FILENAME.
AT SELECTION-SCREEN ON VALUE-REQUEST FOR p_file.
DATA: gdt_filetable TYPE filetable.
DATA:gds_filetable  LIKE LINE OF gdt_filetable .
DATA: gdf_rc          TYPE I.
CALL METHOD cl_gui_frontend_services=>file_open_dialog
   EXPORTING
      WINDOW_TITLE     = 'Choose a file'
   CHANGING
      file_table                 = gdt_filetable
      rc                            = gdf_rc .
IF sy-subrc = 0.
    READ TABLE gdt_filetable
     INTO gds_filetable  INDEX 1.
    p_file = gds_filetable-filename.
ENDIF.
p_fname1 = p_file.
CALL FUNCTION 'RSPO_DOWNLOAD_SPOOLJOB'
  EXPORTING
    id            = SPOOLID
    fname         = p_fname1

Answer 1

Hi the problem is with your function module RSPO_DOWNLOAD_SPOOLJOB not F4 Help.
replace this code, it will solve your problem and check your ID and FNAME parameter values.
IF p_file IS NOT INITIAL AND spoolid IS NOT INITIAL.
    CALL FUNCTION 'RSPO_DOWNLOAD_SPOOLJOB'
      EXPORTING
        id    = spoolid
        fname = p_fname1.
  ENDIF.
Regards
Ahsan