error while creating vendor bank details using MAINTAIN_BAPI of class VMD_ei_api

hi, iam using maintain_bapi of class vmd_ei_api for bank details creation at the time of vendor creation. but im getting error: ' Invalid address:bank Country missing'.please suggest

*    *** Bank details***************************************
    DATA: lt_bankdetails TYPE TABLE OF cvis_ei_cvi_bankdetail,
          ls_bankdetails TYPE cvis_ei_cvi_bankdetail.

    ls_bankdetails-data_key-banks = 'DE'. "Bank Country
    ls_bankdetails-data_key-bankl = 'BEBEDEBB'.     "Bank Key..
    ls_bankdetails-data_key-bankn = '3538174400' ."Bank account number.
    ls_bankdetails-data-bvtyp     = 'USA'.
    ls_bankdetails-data-bkref     = 'BEN'.           "Reference details.
    ls_bankdetails-datax-bvtyp     = 'X'.
    ls_bankdetails-datax-bkref     = 'X'.           "Reference details.
    ls_bankdetails-task            = 'I'.
    ls_bankdetails-data-iban      = 'DE24100200003538174400'.
    ls_bankdetails-datax-iban      = 'X'.
    APPEND  ls_bankdetails TO lt_bankdetails.

*CLEAR : ls_bankdetails.

*    ls_bankdetails-datax-iban      = 'X'.
*   APPEND  ls_bankdetails TO lt_bankdetails.
*  Inserting bank details,,,,
    ls_bank-bankdetails = lt_bankdetails[].
    ls_bank-current_state = ''.
    ls_vendors-central_data-bankdetail = ls_bank.

And second question how/which method to use from this class to update bank details latter. Is it possible after creating vendor with mandatory fields and then update bank details?