ASP.NET 3.5, AJAX, and Web Services

using System;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Xml;
using System.Web.Script.Services;

namespace AjaxWebService
{

    [WebService(Namespace = "http://localhost:49232/AjaxWebService/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    [ScriptService]
    public class Service : System.Web.Services.WebService
    {
        string myXmlData = @"<?xml version=""1.0"" encoding=""utf-8"" ?>
                <Book>
                    <Title>Programming ASP.NET 3.5, AJAX and Web Services</Title>
                </Book>";
        [ScriptMethod(ResponseFormat = ResponseFormat.Json)]
        [WebMethod]
        public string getNextBackupDate(int months)
        {
            return DateTime.Now.AddMonths(months).ToShortDateString();
        }
        
        [ScriptMethod(ResponseFormat = ResponseFormat.Xml)]
        [WebMethod]
        public XmlDocument GetBookTitle()
        {
            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.LoadXml(myXmlData);
            return xmlDoc;
        }
       
        [ScriptMethod(UseHttpGet = true)]
        [WebMethod]
        public string HelloWorld()
        {
            return "Hello, world";
        }

    }
}