title: Event when textbox receive date from Calendar Extender
body: <p>How to have a event when date is selected from Calendar Extender and it does a function in aspx.cs</p>
  
  <pre><code>   Filter by Date:&lt;asp:TextBox ID="txtDatePicker" runat="server"&gt;&lt;/asp:TextBox&gt;
      &lt;ajaxToolkit:CalendarExtender ID="CalendarExtender1" runat="server" Format="dd/MM/yyyy"
             Enabled="True" TargetControlID="txtDatePicker" /&gt;
  </code></pre>