How to enable previous dates from today date in ajax calendar extender

Question

Hi Friends...
 
I have AJAX calender control in my application.
 
But i am not able to select the day before from current date.
 
Only able to select after the current date.
 
What can i Do.


<asp:Label ID="lblstartdate" Text="Start Date" CssClass="lbl" runat="server"></asp:Label> <AjaxToolkit:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server"> </AjaxToolkit:ToolkitScriptManager> <asp:TextBox ID="txtstartdate" CssClass="txtbox" runat="server"></asp:TextBox> <ajaxtoolkit:calendarextender runat="server" ID="calExtender2" PopupButtonID="btnDate3" TargetControlID="txtstartdate" Format="MMMM d, yy" /> <asp:ImageButton ID="btnDate3" ImageUrl="~/images/CalendarIcon.jpg" Width="20px" runat="server" />