custom badi short dump error

i m new to badi i m trying to create custom badi while defination n implementation is done so far all good bt while testing the badi using report i m getting short dump ..

CALL METHOD cl_exithandler=>get_instance

EXPORTING

exit_name = 'zkna1_kunnr_badi_def'

null_instance_accepted = 'X'

• IMPORTING

• ACT_IMP_EXISTING =

CHANGING

instance = l_badi_instance

IF sy-subrc <> 0.

• MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO

• WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.

ENDIF.

*

-

> CALL METHOD l_badi_instance->get_name

EXPORTING

kunnr = p_kunnr

IMPORTING

kna1 = kna1.

i called this l_badi_instance manually .. pls help thsnks in advance