ajax auto complete extender....coding

here i will explain how i have implemented ajax auto complete extender.....it is very useful for beginners nd m also fresher so i understand the problem which we generally face during programming...here is the .aspx page
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>

 <cc1:AutoCompleteExtender ID="AutoCompleteExtender1" runat="server" ServicePath= "WebService.asmx" ServiceMethod="GetCountries" MinimumPrefixLength="1" EnableCaching="true" CompletionSetCount="1" TargetControlID="TextBox1">
        </cc1:AutoCompleteExtender>

nd below is the webservice.asmx page which u can simply include by right click on ur website....

using System.Web.Services.Protocols;
using System.Collections.Generic;
using System.Configuration;
using System.Data.SqlClient;
using System.Data;


[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
[System.Web.Script.Services.ScriptService]
    
public class WebService : System.Web.Services.WebService
    {
        public WebService()
        {
            //Uncomment the following line if using designed components
            //InitializeComponent();
        }
        
        Class1 db=new Class1 ();
    [System.Web.Script.Services.ScriptMethod()]
    [System.Web.Services.WebMethod]
        public List<string>GetCountries(string prefixText)
        {
            db.mycon ();
            SqlCommand cmd = new SqlCommand("select * from stuloginstoreproc where name like @name+'%'", db.con );
            cmd.Parameters.AddWithValue("@name", prefixText);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataTable dt = new DataTable();
            da.Fill(dt);
            List<string> CountryNames = new List<string>();
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                CountryNames.Add(dt.Rows[i][1].ToString());
            }
            return CountryNames;
        }
    }

happy coding frnds