Getting reference to if_ex_cewb_tsk_update

Hi together,

I am trying to use the method CHECK_TSK_AT_SAVE of the BadI: CEWB_TSK_UPDATE. Now the code that I have written is:

DATA: lr_ref      TYPE REF TO if_ex_cewb_tsk_update,
        lt_tsk TYPE STANDARD TABLE OF cpcl_tsk_plko_type.

*  CREATE OBJECT lr_ref.

  CALL METHOD lr_ref->check_tsk_at_save
    EXPORTING
      i_tsk_data          = lt_tsk
*     i_mtk_data          =
*     i_seq_data          =
*     i_plas_data         =
*     i_opr_data          =
*     i_com_data          =
*     i_prt_data          =
*     i_cha_data          =
*     i_chv_data          =
*     i_pac_data          =
*     i_mst_data          =
    EXCEPTIONS
      inconsistency_found = 1
      OTHERS              = 2.
  IF sy-subrc <> 0.
*   Implement suitable error handling here
  ENDIF.

I get the dump: CX_SY_REF_IS_INITIAL, that the interface is not yet initiated, thus we cannot use the method.Can anyone tell me how can I get reference or initiate the lr_ref that I have declared?

Thanks,

R