C#Soap Web服务WSDL

我在asp.net web应用程序中生成了来自wsdl文件的存根.我的问题是如何将这些函数调用添加到httpwebrequest？我已经走到这一步,但不知道如何完成它并在线上发送肥皂.

public httpWebrequest CreateWebrequest(String webMethod)
{
        httpWebrequest webrequest = (httpWebrequest)Webrequest.Create("");
        webrequest.Headers.Add(@"SOAPAction","\"http://www.multispeak.org/Version_3.0/"+ webMethod +"\"");
        webrequest.ContentType = "text/xml;charset=\"utf-8\"";
        webrequest.Accept = "text/xml";
        webrequest.Method = "POST";
        return webrequest;
}


protected void Button1_Click(object sender,EventArgs E)
    {
        MR_ServerSoapClient soapClient = new MR_ServerSoapClient(endPoint,uri);
        PingURLrequest request = new PingURLrequest();
        PingURLResponse response = new PingURLResponse();

    }

using (var response = (httpWebResponsE)webrequest.GetResponse())
{
   var reader = new StreamReader(response.GetResponseStream());
   var result = reader.ReadToEnd();
}