error in field catalog in ALV grid display using classes at do_sum = "X'.

Hi,

I'm using classes in ALV Grid display.

the code for the field catalog is going to dump because of the statement in the field catalog for field 'netwr',do_sum = 'X'.

that do_sum = 'X' is not working and going to dump when executed.with out that do_sum it is working fine. the error in dump analysys is showing sap standard incude LSLVCF01.

assign component

<ls_fieldcat>-fieldname of structure rt_data to <g_field>.

if sy-subrc ne 0.

message x000(0k).

endif.

sy-subrc is 4 when the program is being executed.

CODE:

FORM prepare_field_catalog CHANGING pt_fieldcat TYPE lvc_t_fcat.

DATA ls_fcat TYPE lvc_s_fcat.

ls_fcat-fieldname = 'VBELN1'.

ls_fcat-ref_field = 'VBELN'.

ls_fcat-ref_table = 'VBRK'.

ls_fcat-coltext = 'Invoice No'.

ls_fcat-seltext = 'Invoice No'.

APPEND ls_fcat TO pt_fieldcat.

CLEAR ls_fcat.

ls_fcat-fieldname = 'BUDAT'.

ls_fcat-ref_table = 'BKPF'.

ls_fcat-coltext = 'Invoice Date'.

ls_fcat-seltext = 'Invoice Date'.

APPEND ls_fcat TO pt_fieldcat.

CLEAR ls_fcat.

ls_fcat-fieldname = 'NETWR'.

ls_fcat-ref_field = 'NETWR'.

ls_fcat-ref_table = 'VBRK'.

ls_fcat-coltext = 'Value of Invoice'.

ls_fcat-seltext = 'Value of Invoice'.

ls_fcat-datatype = 'CURR'.

ls_fcat-do_sum = 'X'.

APPEND ls_fcat TO pt_fieldcat.

CLEAR ls_fcat.

ENDFORM.

can u please look in the code and rectify the error,

would appeciate ur response.

regards,

veera.