Visual Basic

        Dim env As SoapEnvelope
        Dim epr As EndpointReference
        Dim client As MyHttpClient
        Dim rs As SoapEnvelope
        Dim bodyResponse As String
        Dim web_namespace As String
        Dim web_uri As String
        Dim web_method As String
        Dim action As String
        Dim inner_xml As String
 
        web_method = MethodTextBox.Text.Trim
        web_uri = WebServiceURLTextBox.Text.Trim
        web_namespace = NamespaceTextBox.Text.Trim
 
        If web_namespace.EndsWith("/") = False Then
            web_namespace += "/"
        End If
 
        action = web_namespace & web_method
 
        inner_xml = "<" & web_method & " xmlns=""" & web_namespace & """" & " ><first_name>Test</first_name><last_name>User</last_name></HelloWorld>"
 
        env = New SoapEnvelope
        env.Context.Addressing.Action = New Action(action)
        env.CreateBody()
 
        env.Body.InnerXml = String.Format(inner_xml)
        epr = New EndpointReference(New Uri(web_uri))
        client = New MyHttpClient(epr)
 
        client.WebAction = action
        rs = client.TestWebRequest(env)
        bodyResponse = rs.Body.OuterXml
        TestReport.Text = bodyResponse
    End Sub
End Class
 
 
 
Option Explicit On 
Option Strict On
 
Imports System.Xml
Imports Microsoft.Web.Services2
Imports Microsoft.Web.Services2.Addressing
Imports Microsoft.Web.Services2.Messaging
Imports System.Web
 
Public Class MyHttpClient
    Inherits SoapClient
 
    Friend intWebAction As String
 
    WriteOnly Property WebAction() As String
        Set(ByVal Value As String)
            intWebAction = Value
        End Set
    End Property
 
    Public Sub New(ByVal dest As EndpointReference)
        MyBase.New(dest)
    End Sub
 
    '"http://tempuri.com/TestWebService/MyService/HelloWorld")> _
    <SoapMethod("http://tempuri.com/TestWebService/MyService/HelloWorld")> _
    Public Function TestWebRequest(ByVal envelope As SoapEnvelope) As SoapEnvelope
        Dim response As SoapEnvelope
        Dim msg As String
 
        response = MyBase.SendRequestResponse("HelloWorld", envelope)
        msg = response.Body.OuterXml
 
        TestWebRequest = response
    End Function
 
    Protected Overrides Sub FilterMessage(ByVal envelope As Microsoft.Web.Services2.SoapEnvelope)
        MyBase.FilterMessage(envelope)
    End Sub
End Class


WebMethod is:

<WebMethod()> _
    Public Function HelloWorld(ByVal first_name As String, ByVal last_name As String) As String
        Return "Hello " + first_name + " " + last_name + "!"
    End Function