using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;

namespace ws
{
    [WebService(Namespace = "http://www.testing.com/TestV")]
    [System.Web.Services.WebServiceBindingAttribute(Name = "TestBind", 
        Namespace = "http://www.testing.com/TestV")]
    public class Test : System.Web.Services.WebService
    {

        [System.Web.Services.Protocols.SoapDocumentMethodAttribute("", 
            Use = System.Web.Services.Description.SoapBindingUse.Literal, 
            ParameterStyle = System.Web.Services.Protocols.SoapParameterStyle.Bare)]
        [return: System.Xml.Serialization.XmlElementAttribute("HelloWorld",
            Namespace = "http://www.testing.com/TestV")]
        [WebMethod]
        public string HelloWorld()
        {
            return "Hello World";
        }
    }
}

<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
  <soap:Body>
    <HelloWorld xmlns="http://www.testing.com/TestV">Hello World</HelloWorld>
  </soap:Body>
</soap:Envelope>

<?xml version="1.0" encoding="utf-8"?>
<soapenv:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
	xmlns:soapenv ="http://schemas.xmlsoap.org/soap/envelope/">
  <soapenv:Body>
    <HelloWorld xmlns="http://www.testing.com/TestV">Hello World</HelloWorld>
  </soapenv:Body>
</soapenv:Envelope>