domino web service使用者相关问题

%INCLUDE "lsxsd.lss"
Const n0 = "xxxxxxxxxxxxxxxxxxxxxxxxxxx"
Class MessageServicePortType_n0 As PortTypeBase

Sub NEW
    Call Service.Initialize ("HttpServiceWsSmsRyoukaComMessageService", _
    "MessageService.MessageServiceHttpPort", "http://1xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", _
    "MessageServicePortType_n0")

End Sub

Function sendMessage(in0 As XSD_STRING) As XSD_STRING
    Set sendMessage = Service.Invoke("sendMessage", in0)
End Function

Function queryMessage(in0 As XSD_STRING) As XSD_STRING
    Set queryMessage = Service.Invoke("queryMessage", in0)
End Function

Function queryReply(in0 As XSD_STRING) As XSD_STRING
    Set queryReply = Service.Invoke("queryReply", in0)
End Function

End Class
如何调用这个web service使用者 之中的sendmessage函数
Sub Initialize()
Dim sstr As XSD_STRING
Dim MessageServicePortType_n01 As MessageServicePortType_n0
Set MessageServicePortType_n01 = New MessageServicePortType_n0
MsgBox MessageServicePortType_n01.sendMessage("sstr")
End Sub
这样为什么会报错呢

参考：http://blog.csdn.net/zys5212/article/details/6707440