Autocomplete textbox not working Asp.net

Question

My Code

 

This Part Working Properly

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Data.SqlClient;
using System.Configuration;
using System.Web.Script.Services;
namespace Product
{
/// <summary>
/// Summary description for CustService
/// </summary>
[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
[System.ComponentModel.ToolboxItem(false)]
// 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 CustService : System.Web.Services.WebService
{
[WebMethod]
[ScriptMethod(ResponseFormat = ResponseFormat.Json)]
public List<string> GetAutoCompleteData(string name)
{
List<string> result = new List<string>();
using (SqlConnection con = new SqlConnection(@"Data Source=KARUKUVELRAJ-PC\SQLEXPRESS;Initial Catalog=Product;Integrated Security=True"))
{
using (SqlCommand cmd = new SqlCommand("select DISTINCT name from customer where name LIKE '%'+@SearchText+'%'", con))
{
con.Open();
cmd.Parameters.AddWithValue("@SearchText", name);
SqlDataReader dr = cmd.ExecuteReader();
while (dr.Read())
{
result.Add(dr["name"].ToString());
}
return result;
}
}
}
}
}

<asp:ScriptManager ID="ScriptManager1" runat="server" EnablePageMethods="True">

</asp:ScriptManager>

<asp:TextBox ID="txtName" runat="server" Font-Bold="False" CssClass="form-control"></asp:TextBox>

<ajaxToolkit:AutoCompleteExtender ID="AutoCompleteExtender1" runat="server" ServiceMethod="GetAutoCompleteData" CompletionInterval="10" EnableCaching="False" TargetControlID="txtName" ServicePath="~/CustService.asmx"> </ajaxToolkit:AutoCompleteExtender>

 

I Run This Code Not invoke it not Response, How to Clear this Problem