SOAP client Error says Path property must be set before calling the Send method ?

[John Elliott]

I am trying to write a simple SOAP client in VB.net and wanted to
test it using the SOAP demo server at
http://www.whitemesa.com/interop/InteropTest.wsdl

I successfully created the web reference to the above site in VB.net.

I then created a command button to invoke the method echoInteger(),
see code below for my button.

But when I click the button, I get the following error messages:

An unhandled exception of type 'System.InvalidOperationException' occurred
in system.web.services.dll
Additional information: Path property must be set before calling the Send
method.

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim myInteger As Integer
Dim myInputInteger As Integer
myInputInteger = 9999
Dim cc As com.whitemesa.www.InteropTestSoapBinding
cc = New com.whitemesa.www.InteropTestSoapBinding
myInteger = cc.echoInteger(myInputInteger)
End Sub

I am a newbie at SOAP and webservice programming.
Can someone help tell me what I am doing wrong?
Thanks in advance. - John Elliott