jQuery UI AutoComplete using Generic Handler in ASP.Net Master Page

am using site.master page the second webform withmaster page am trying add autocomplete from admin folder not working

from root working very well

what is wrong with  my code

<%@ Page Title="" Language="C#" MasterPageFile="~/Site1.Master" AutoEventWireup="true" codefile="WebForm2.aspx.cs" Inherits="gsc.Admin.WebForm2" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">
 
 <link href="css/jquery.autocomplete.css" rel="stylesheet" type="text/css" />
<script src="scripts/jquery-1.4.1.min.js" type="text/javascript"></script>
<script src="scripts/jquery.autocomplete.js" type="text/javascript"></script>
<script type="text/javascript">
    $(document).ready(function () {
        $("#<%=txtSearch.ClientID%>").autocomplete('~/Admin/Search_CS.ashx');
    });       
</script>   
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
    <div>
        <asp:TextBox ID="txtSearch" runat="server"></asp:TextBox>
    </div>                       
</asp:Content>