<%@ Page Title="Web Services Demo" Language="C#" MasterPageFile="~/MasterPages/MasterPage.master" AutoEventWireup="true" CodeFile="WebServices.aspx.cs" Inherits="Demos_WebServices" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">
</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="cpMainContent" Runat="Server">
  <asp:ScriptManagerProxy ID="ScriptManagerProxy1" runat="server">
      <Services> 
        <asp:ServiceReference Path="~/WebServices/NameService.asmx" />
      </Services>
  </asp:ScriptManagerProxy>

  <input id="txtYourName" type="text" name="txtYourName" />
  <input id="btnSayHello" type="button" value="Say Hello" />
  <script type="text/javascript">
    function HelloWorld() 
    {
      var yourName = $get('txtYourName').value;
      NameService.HelloWorld(yourName, HelloWorldCallback);
    }
    function HelloWorldCallback(result) 
    {
      alert(result);
    }
    
    $addHandler($get('btnSayHello'), 'click', HelloWorld);
  
  </script>
  
</asp:Content>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Demos_WebServices : BasePage
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
}

<%@ WebService Language="C#" CodeBehind="~/App_Code/NameService.cs" Class="NameService" %>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;

/// <summary>
/// Summary description for NameService
/// This is the code-behind for the Web Service NameService.asmx.
/// Visual Studio automatically puts the code-behind for a web service into the App_Code folder.
/// </summary>
[WebService(Namespace = "http://tempuri.org/")]

[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line. 

[System.Web.Script.Services.ScriptService]
public class NameService : System.Web.Services.WebService 
{
        public NameService () 
    {
        //Uncomment the following line if using designed components 
        //InitializeComponent(); 
    }

    [WebMethod]
    public string HelloWorld(string firstName, string lastName)
    {
        return string.Format("Hello {0} {1}", firstName, lastName);
    }
    
   
}