AjaxControlToolkit CalendarExtender control not working

Dear All,
 
I am using CalendarExtender in my project.But It is not working. I have added latest AjaxToolKit.dll.
 
there is a ToolkitScriptManager in master page.
 

<cc1:ToolkitScriptManager ID="ScriptManager" runat="server"></cc1:ToolkitScriptManager>

 
and dll registerd in web.config like this:
 

<add assembly="AjaxControlToolkit" namespace="AjaxControlToolkit" tagPrefix="cc1" />

 
Here is code spinet:
 

<asp:TextBox ID="txtdtofRegi" runat="server" CssClass="input_text"></asp:TextBox><cc1:CalendarExtender ID="CalendarExtender1" EnabledOnClient="true" runat="server"
                                                                TargetControlID="txtdtofRegi" PopupButtonID="txtdtofRegi" Format="MMMM d, yyyy"></cc1:CalendarExtender>

 

also I downloaded sample project of controltoolkit. but its controls also not working.
when I clicked for calendarExtender in textbox it not show calendar.
 
I have tried in Mozilla Firefox 5.0 and IE 6
 
I am not getting problem. please and please help me..
 
Thanks..