User exit for Infotype 0102 - Grevience

Question

Hi all,
I have a requirement where i have to put a check on infotype 0102 - greivence NA through user exit EXIT_SAPFP50M_002 .
The check is that if the user enters a personnel number , grievence number and a stage for which the record alreday exist in the table for the same personnel number , then system should pp up an error message.
I wrote the below code in EXIT_SAPFP50M_002 :-
data : i0102 like p0102 occurs 3 with header line,
begin of fs2,
pernr like p0102-pernr, grnum like p0102-grnum, grstg like p0102-grstg,
end of fs2.
CASE INNNN-INFTY.
WHEN '0102'.
MOVE INNNN TO I0102.
LOOP AT SCREEN.
SELECT PERNR GRNUM GRSTG FROM PA0102 INTO corresponding fields of fs2 WHERE PERNR = I0102-PERNR.
IF fs2-GRNUM = I0102-GRNUM ANd fs2-GRSTG = I0102-GRSTG.
MESSAGE 'A record already exist for selected combination of Grievence Number and Stage' type 'e'.
endif.
ENDLOOP.
ENDCASE.
Here system is throwing an error as " i0102 and innnn are not mutually convertible".
I tried to use a metod :
<b>cl_hr_pnnnn_type_cast=>prelp_to_pnnnn</b>
but still same error :
call method cl_hr_pnnnn_type_cast=>prelp_to_pnnnn
exporting
prelp = innnn
importing
pnnnn = i0102.
MOVE INNNN TO I0102.
LOOP AT SCREEN.
SELECT PERNR GRNUM GRSTG FROM PA0102 INTO corresponding fields of fs2 WHERE PERNR = I0102-PERNR.
IF fs2-GRNUM = I0102-GRNUM ANd fs2-GRSTG = I0102-GRSTG.
MESSAGE 'A record already exist for selected combination of Grievence Number and Stage' type 'e'.
endif.
ENDLOOP.
Please suggest what to do.
Thanks and regards
Ribhu

Answer 1

Hello Ribhu
Perhaps the following coding may be useful:
* define local data
  DATA:
    ls_p0102      TYPE p0102,
    fs2           TYPE pa0102.
  CALL METHOD cl_hr_pnnnn_type_cast=>prelp_to_pnnnn
    EXPORTING
      prelp = innnn
    IMPORTING
      pnnnn = ls_p0102.
  "  LOOP AT SCREEN.  " ???
  SELECT pernr grnum grstg FROM pa0102
    INTO CORRESPONDING FIELDS OF fs2
    WHERE pernr = ls_p0102-pernr.
    EXIT.
  ENDSELECT.
  IF ( fs2-grnum = ls_p0102-grnum    AND
       fs2-grstg = ls_p0102-grstg ).
    MESSAGE e398(00) WITH text-err
      RAISING error_occured.
  ENDIF.
  "  ENDLOOP.  " ???
Regards
  Uwe