problem while updating asset master using bapi

dear all

i trying to update asse master using FM  BAPI_FIXEDASSET_CHANGE,

i got an error :"W_EXTENSIONIN-VALUEPART1" and "L_BAPI_TE_ANLU" cannot be converted to each other in a Unicode system. Here, the conversion involves a conversion between a structure and a single field.'

please help.thanks for the help in advance.

this is a part of source code :

DATA L_BAPI_TE_ANLU type BAPI_TE_ANLU.

   DATA W_EXTENSIONIN TYPE BAPIPAREX.

   DATA LT_EXTENSIONIN LIKE BAPIPAREX OCCURS 0 WITH HEADER LINE.

   L_BAPI_TE_ANLU-ZCNENG = LT_ZCOJTCL-ZCNENG.

  L_BAPI_TE_ANLU-Zmein = LT_ZCOJTCL-Zmein.

    W_EXTENSIONIN-STRUCTURE = 'BAPI_TE_ANLU'.

    W_EXTENSIONIN-VALUEPART1 = L_BAPI_TE_ANLU.

APPEND W_EXTENSIONIN TO   LT_EXTENSIONIN.

`````````````````````````````

CALL FUNCTION 'BAPI_FIXEDASSET_CHANGE'

   EXPORTING

     COMPANYCODE                = '6000'

     ASSET                      = LT_ZCOJTCL-ZANLN1

    SUBNUMBER                  = '0000'

    GENERALDATA                = L_GENERALDATA

    GENERALDATAX               = L_GENERALDATAX

    TIMEDEPENDENTDATA          = L_TIMEDEPENDENTDATA

    TIMEDEPENDENTDATAX         = L_TIMEDEPENDENTDATAX

  IMPORTING

    RETURN                     = L_RETURN

  TABLES

    EXTENSIONIN                = LT_EXTENSIONIN .