ajax controls are not working in asp.net
<p>I am trying to put a calender extender in my aspx page but it is not working and showing no error, but when i try to do this at another project so its working.
what is the problem with my current page ? plz help me.
my code is .......</p>

<p>below is my code</p>

<pre><code>&lt;%@ Page Title="" Language="C#" MasterPageFile="~/site.Master" AutoEventWireup="true" CodeBehind="Add Tax.aspx.cs" Inherits="HMS.Add_Tax" %&gt;

&lt;%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="asp" %&gt;
&lt;asp:Content ID="Content1" ContentPlaceHolderID="HeadContent" runat="server"&gt;
&lt;tr&gt;
        &lt;asp:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server"&gt;&lt;/asp:ToolkitScriptManager&gt; 
        &lt;td class="auto-style2"&gt;Applies From&lt;/td&gt;
        &lt;td class="auto-style10"&gt;                 
            &lt;asp:TextBox ID="txtdate" runat="server"&gt;&lt;/asp:TextBox&gt;                
            &lt;asp:CalendarExtender ID="CalendarExtender1" runat="server" TargetControlID="txtdate" PopupButtonID="txtdate" Format="dd/MM/yyyy" Enabled="true"&gt;
            &lt;/asp:CalendarExtender&gt;
        &lt;/td&gt;
</code></pre>