how to call java webservice in vb 6

I am trying to call java web service method in vb6, but always error..
i use SOAP type library v 3.0..
The error is :

Client : Incorrect number of parameters supplied for SOAP request
HRESULT=0x80070057: The parameters is incorrect.
- CLient:Unspecified client error, HRESULT=0x080070057: The parameter is incorrect

this is my listing code :

Private Sub Command8_Click()

Dim clientSOAP As SoapClient30
Set clientSOAP = New SoapClient30
Dim port As New WSDLPort

clientSOAP.mssoapinit "http://dealerhondabali.com:8080/TambahSPKService/TambahSPKService?WSDL;

Dim nResult As Integer
Dim strResult As String

'================method insertDataSPK===============
Dim spkTanggal As String
Dim posId As String
Dim slsId As String
Dim spkNoKtpFakturStnk As String
Dim spkNamaFakturStnk As String
Dim spkAlamatFakturStnk As String
Dim spkKelurahanFakturStnk As String
Dim spkJenisPenjualan As Integer
Dim spkLeasing As String
Dim spkDownPayment As String
Dim spkTenor As String
Dim spkJenisBunga As String
Dim dlrCodeHso As String
Dim createBy As String
Dim createDate As String
Dim updateBy As String
Dim updateDate As String

spkTanggal = "21/06/2012"
posId = "09221001"
slsId = "203872"
spkNoKtpFakturStnk = "5108023112790062"
spkNamaFakturStnk = "I Made Testing"
spkAlamatFakturStnk = "Jalan street gang line"
spkKelurahanFakturStnk = "14"
spkJenisPenjualan = "1"
spkLeasing = "1"
spkDownPayment = "500000"
spkTenor = "36"
spkJenisBunga = "menurun"
dlrCodeHso = "00637"
createBy = "user"
createDate = "21/06/2012"
updateBy = "user"
updateDate = "21/06/2012"

nResult = clientSOAP.insertDataSPK(spkTanggal, posId, slsId, spkNoKtpFakturStnk, spkNamaFakturStnk, _
spkAlamatFakturStnk, spkKelurahanFakturStnk, spkJenisPenjualan, _
spkLeasing, spkDownPayment, spkTenor, spkJenisBunga, dlrCodeHso, createBy, _
createDate, updateBy, updateDate)

End Sub

can any one please help me.
Thank you

Tags: Service, Web Development