Error while closing F4 help window

Question

I have used FM F4IF_INT_TABLE_VALUE_REQUEST, to add F4 help to input element of my screen, but when I try to select a value from the list or close the input help window, the control goes to dump with following error message:
The program attempted to issue a " " message during "F4" processing.
This is an illegal operation.
The program was terminated.
I am using the following code:
  CALL FUNCTION 'F4IF_INT_TABLE_VALUE_REQUEST'
    EXPORTING
      retfield               = 'LIFNR'
      dynpprog               = sy-repid
      dynpnr                 = sy-dynnr
      dynprofield            = 'WA_YCT3-LIFNR'
      value_org              = 'S'
    TABLES
      value_tab              = it_lfa1
   EXCEPTIONS
      parameter_error        = 1
     no_values_found        = 2             
     OTHERS                 = 3.
  IF sy-subrc = 1.
    RAISE parameter_error.
  ELSEIF sy-subrc = 2.
    RAISE no_values_found.
  ELSE.
    MESSAGE 'Unknown error occured while processing request' TYPE 'E'.
  ENDIF.
ENDMODULE.

Answer 1

Hi Das,
This time i have tried one code and i am able to get the F4 help for LIFNR field correctly. Copy paste the code and execute it will work....
data: begin of itab occurs 0,
lifnr like lfa1-lifnr,
end of itab.
DATA : return like ddshretval occurs 0 with header line.
data: begin of dynpfields occurs 0.
include structure dynpread.
data: end of dynpfields.
parameters: p_lifnr like LFA1-LIFNR.
Initialization.
AT SELECTION-SCREEN ON VALUE-REQUEST FOR P_LIFNR.
REFRESH ITAB.
SELECT lifnr FROM lfa1 INTO TABLE ITAB.
call function 'F4IF_INT_TABLE_VALUE_REQUEST'
EXPORTING
retfield = 'lifnr'
dynprofield = 'P_lifnr'
dynpprog = sy-REPID
dynpnr = sy-dynnr
value_org = 'S'
TABLES
value_tab = ITAB
return_tab = return.
p_lifnr = return-fieldval.
refresh return.
clear return.
Hope my answer helps you.
Cheers!!