Any wrong with my code?

I have following code in order to update customer field in EBAN, but it shows ABAP dump. Anything is wrong?

DATA: it_extension TYPE STANDARD TABLE OF bapiparex.
DATA: wa_extension TYPE bapiparex.
DATA: wa_bapi_te_mereqitem TYPE bapi_te_mereqitem.
wa_bapi_te_mereqitem-preq_item = '00010'.
wa_bapi_te_mereqitem-zpernr = '12345678'.

MOVE:
wa_bapi_te_mereqitem-preq_item TO wa_extension-valuepart1+0(5),
wa_bapi_te_mereqitem-zpernr    TO wa_extension-valuepart1+5(8).

MOVE 'BAPI_TE_MEREQITEM ' TO wa_extension-structure.
APPEND wa_extension TO it_extension.
CALL FUNCTION 'BAPI_PR_CHANGE'
  EXPORTING
    prnumber                    = '0010012923'
 TABLES
   extensionin                 = it_extension      .
COMMIT WORK AND WAIT .

Edited by: Matt on Oct 15, 2009 10:50 AM - added tags