AutoComplete not working

Hey there, 

start working with .net 4.5.1 and AjaxControlToolkit (installed by Nuget). 

I created an example but it won't work, there is no firing of the web method.

WebService File

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

namespace AutoComplete
{
    /// <summary>
    /// Zusammenfassungsbeschreibung für AutoComplete
    /// </summary>
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    [System.ComponentModel.ToolboxItem(false)]
    // Wenn der Aufruf dieses Webdiensts aus einem Skript mithilfe von ASP.NET AJAX zulässig sein soll, heben Sie die Kommentarmarkierung für die folgende Zeile auf. 
    // [System.Web.Script.Services.ScriptService]
    public class AutoComplete : System.Web.Services.WebService
    {

        [WebMethod]
        public List<string> GetStates(string prefixText, int count)
        {
            List<string> states = new List<string>() { "Alaska", "Alabama", "California", "North Dakota" };

            return states;
        }

    }
}

and the apsx

<%@ Page Language="C#"  MasterPageFile="~/Site.Master"  AutoEventWireup="true" CodeBehind="Test.aspx.cs" Inherits="AutoComplete._Default" %><asp:Content ID="Content1" ContentPlaceHolderID="MainContent" runat="server"><asp:TextBox ID="txtStates" runat="server"></asp:TextBox><ajaxToolkit:AutoCompleteExtender ID="autoCompleteStates" runat="server" 
      DelimiterCharacters="" Enabled="True" TargetControlID="txtStates" ServiceMethod="GetStates" 
        MinimumPrefixLength="1" ServicePath="~/AutoComplete.asmx" CompletionInterval="200"></ajaxToolkit:AutoCompleteExtender></asp:Content>

there no action, just nothing... 

please help!