Error in Drilled down ALV Report.

Question

Hi all
i am creating a single level drilled down report , in that in the first screen i am displaying the header detials , in the second level i am displaying the item detial of the particular line..
While processing the second level i am getting a dump like
A PERFORM was used to call the routine "USER_COMMAND" of the program
"SAPLSLVC_FULLSCREEN".
This routine contains exactly 1 formal parameters, but the current
call contains 2 actual parameters.
parameters.
here is my code :
FORM USER_COMMAND USING R_UCOMM LIKE SY-UCOMM.
CASE R_UCOMM.
WHEN '&IC1'.
PERFORM BUILD_CATALOG_EKPO.
PERFORM EVENT_EKPO.
PERFORM POPULATE_EVENT_EKPO.
PERFORM DATA_EKPO.
PERFORM BUILD_LIST.
PERFORM DISPLAY_EKPO.
ENDCASE.
ENDFORM.
*&      Form  BUILD_CATALOG_EKPO
      text
-->  p1        text
<--  p2        text
FORM BUILD_CATALOG_EKPO .
  WA_FIELDCAT-TABNAME = 'ITAB_EKPO'.
  WA_FIELDCAT-FIELDNAME = 'EBELN'.
  WA_FIELDCAT-SELTEXT_M = 'PO NO.'.
  APPEND WA_FIELDCAT TO I_FIELDCAT.
  CLEAR WA_FIELDCAT.
  WA_FIELDCAT-TABNAME = 'ITAB_EKPO'.
  WA_FIELDCAT-FIELDNAME = 'EBELP'.
  WA_FIELDCAT-SELTEXT_M = 'Item No.'.
  APPEND WA_FIELDCAT TO I_FIELDCAT.
  CLEAR WA_FIELDCAT.
    WA_FIELDCAT-TABNAME = 'ITAB_EKPO'.
  WA_FIELDCAT-FIELDNAME = 'MATNR'.
  WA_FIELDCAT-SELTEXT_M = 'Material NO.'.
  APPEND WA_FIELDCAT TO I_FIELDCAT.
  CLEAR WA_FIELDCAT.
    WA_FIELDCAT-TABNAME = 'ITAB_EKPO'.
  WA_FIELDCAT-FIELDNAME = 'WERKS'.
  WA_FIELDCAT-SELTEXT_M = 'PLANT.'.
  APPEND WA_FIELDCAT TO I_FIELDCAT.
  CLEAR WA_FIELDCAT.
    WA_FIELDCAT-TABNAME = 'ITAB_EKPO'.
  WA_FIELDCAT-FIELDNAME = 'LGORT'.
  WA_FIELDCAT-SELTEXT_M = 'Storage Loc.'.
  APPEND WA_FIELDCAT TO I_FIELDCAT.
  CLEAR WA_FIELDCAT.
    WA_FIELDCAT-TABNAME = 'ITAB_EKPO'.
  WA_FIELDCAT-FIELDNAME = 'MENGE'.
  WA_FIELDCAT-SELTEXT_M = 'Quantity.'.
  APPEND WA_FIELDCAT TO I_FIELDCAT.
  CLEAR WA_FIELDCAT.
    WA_FIELDCAT-TABNAME = 'ITAB_EKPO'.
  WA_FIELDCAT-FIELDNAME = 'MEINS'.
  WA_FIELDCAT-SELTEXT_M = 'UNIT.'.
  APPEND WA_FIELDCAT TO I_FIELDCAT.
  CLEAR WA_FIELDCAT.
ENDFORM.                    " BUILD_CATALOG_EKPO
*&      Form  EVENT_EKPO
      text
-->  p1        text
<--  p2        text
FORM EVENT_EKPO .
CALL FUNCTION 'REUSE_ALV_EVENTS_GET'
EXPORTING
  I_LIST_TYPE           = 0
IMPORTING
   ET_EVENTS             = V_EVENTS
EXCEPTIONS
  LIST_TYPE_WRONG       = 1
  OTHERS                = 2
IF SY-SUBRC <> 0.
MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
        WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.
ENDFORM.                    " EVENT_EKPO
*&      Form  POPULATE_EVENT_EKPO
      text
-->  p1        text
<--  p2        text
FORM POPULATE_EVENT_EKPO .
READ TABLE V_EVENTS INTO WA_EVENT WITH KEY NAME = 'TOP_OF_PAGE'.
IF SY-SUBRC EQ 0.
WA_EVENT-FORM = 'TOP_OF_PAGE'.
MODIFY V_EVENTS FROM WA_EVENT TRANSPORTING FORM WHERE NAME = WA_EVENT-FORM.
ENDIF.
ENDFORM.                    " POPULATE_EVENT_EKPO
FORM F_TOP_OF_PAGE.
  CALL FUNCTION 'REUSE_ALV_COMMENTARY_WRITE'
    EXPORTING
      IT_LIST_COMMENTARY       = IT_LISTHEADER
   i_logo                   =
   I_END_OF_LIST_GRID       =
ENDFORM.
*&      Form  DATA_EKPO
      text
-->  p1        text
<--  p2        text
FORM DATA_EKPO .
DATA:RS_SELFIELD TYPE SLIS_SELFIELD.
READ TABLE ITAB_EKKO INTO WA_EKKO INDEX RS_SELFIELD-TABINDEX.
SELECT EBELN EBELP MATNR WERKS LGORT MENGE MEINS
FROM EKPO
INTO CORRESPONDING FIELDS OF TABLE ITAB_EKPO
WHERE EBELN = WA_EKKO-EBELN.
DATA :ID_ITEM_COLOR.
LOOP AT ITAB_EKPO INTO WA_EKPO.
ID_ITEM_COLOR = ID_ITEM_COLOR + 1.
IF ID_ITEM_COLOR = 8.
   ID_ITEM_COLOR = 1.
ENDIF.
CONCATENATE 'C' ID_ITEM_COLOR '10' INTO WA_EKPO-LINE_COLOR_ITEM.
MODIFY ITAB_EKPO FROM WA_EKPO TRANSPORTING LINE_COLOR_ITEM.
ENDLOOP.
ENDFORM.                    " DATA_EKPO
*&      Form  DISPLAY_EKPO
      text
-->  p1        text
<--  p2        text
FORM DISPLAY_EKPO .
CALL FUNCTION 'REUSE_ALV_GRID_DISPLAY'
EXPORTING
  I_INTERFACE_CHECK                 = ' '
  I_BYPASSING_BUFFER                = ' '
  I_BUFFER_ACTIVE                   = ' '
   I_CALLBACK_PROGRAM                 = V_REPID
  I_CALLBACK_PF_STATUS_SET          = ' '
  I_CALLBACK_USER_COMMAND           = 'USER_COMMAND '
  I_CALLBACK_TOP_OF_PAGE            = 'TOP_OF_PAGE'
  I_CALLBACK_HTML_TOP_OF_PAGE       = ' '
  I_CALLBACK_HTML_END_OF_LIST       = ' '
  I_STRUCTURE_NAME                  =
  I_BACKGROUND_ID                   = ' '
   I_GRID_TITLE                      = I_TITLE_EKPO
  I_GRID_SETTINGS                   =
  IS_LAYOUT                         =
   IT_FIELDCAT                       = I_FIELDCAT[]
  IT_EXCLUDING                      =
  IT_SPECIAL_GROUPS                 =
  IT_SORT                           =
  IT_FILTER                         =
  IS_SEL_HIDE                       =
  I_DEFAULT                         = 'X'
  I_SAVE                            = ' '
  IS_VARIANT                        =
   IT_EVENTS                         = V_EVENTS
  IT_EVENT_EXIT                     =
  IS_PRINT                          =
  IS_REPREP_ID                      =
  I_SCREEN_START_COLUMN             = 0
  I_SCREEN_START_LINE               = 0
  I_SCREEN_END_COLUMN               = 0
  I_SCREEN_END_LINE                 = 0
  IT_ALV_GRAPHICS                   =
  IT_HYPERLINK                      =
  IT_ADD_FIELDCAT                   =
  IT_EXCEPT_QINFO                   =
  I_HTML_HEIGHT_TOP                 =
  I_HTML_HEIGHT_END                 =
IMPORTING
  E_EXIT_CAUSED_BY_CALLER           =
  ES_EXIT_CAUSED_BY_USER            =
  TABLES
    T_OUTTAB                          = ITAB_EKPO
EXCEPTIONS
  PROGRAM_ERROR                     = 1
  OTHERS                            = 2
IF SY-SUBRC <> 0.
MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
        WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.
ENDFORM.                    " DISPLAY_EKPO
*&      Form  BUILD_LIST
      text
-->  p1        text
<--  p2        text
FORM BUILD_LIST .
  gd_layout-no_input          = 'X'.
  gd_layout-colwidth_optimize = 'X'.
  gd_layout-totals_text       = 'Totals'(201).
Set layout field for row attributes(i.e. color)
  gd_layout-info_fieldname =      ' LINE_COLOR_ITEM'.
ENDFORM.                    " BUILD_LIST
Arun Joseph

Answer 1

The form USER_COMMAND should have 2 changing/actual parameters which is standard.
Ex:
FORM user_command USING r_ucomm LIKE sy-ucomm 
rs_selfield TYPE slis_selfield.
ENDFORM.