title: ASP.Net AjaxControlToolkit CalendarExtender not updating Textbox in code behind
body: <p>Have the following:</p>
  
  <pre><code>&lt;asp:TextBox ID="txtStart" runat="server" Enabled="false"&gt;&lt;/asp:TextBox&gt;
  &lt;asp:Image ID="ibDateS" runat="server" ImageUrl="../SystemImages/calendar.gif" ToolTip="Click to show calendar" AlternateText="Click to show calendar" CssClass="showpointer" /&gt;                                                
  &lt;ajaxToolkit:CalendarExtender ID="ceStart" PopupButtonID="ibDateS" Format="dd/MM/yyyy" TargetControlID="txtStart" runat="server"&gt;&lt;/ajaxToolkit:CalendarExtender&gt;
  </code></pre>
  
  <p>It all works ok on the DOM and the textbox gets updated with the new date BUT when I try to get the value in code behind i.e. txtStart.Text it still has the original value set on Page_Load.</p>
  
  <p>Have I missed something?</p>
  
  <p>EDIT:
  TextBox set originally in Page_Load (yes contained in if(!IsPostback)):</p>
  
  <pre><code>txtStart.Text = DateTime.Now.ToString("dd/MM/yyyy");
  </code></pre>
  
  <p>Get it later like so:</p>
  
  <pre><code>DateTime dtStart = Convert.ToDateTime(txtStart.Text);
  </code></pre>