title: Popupextender disappears after postback in Usercontrol
body: <p>Dear Fellows i have a usercontrol which takes destination details from users with multiple dropdownlist controls... 
  e.g. Country Dropdownlist produces postback and populate states dropdownlist based on select values. State's Dropdownlist produces postback to get cities based on states.Furthermore everything happens in an Ajax UpdatePanel.
      
      
      
            --Select--
        </p>
  
  <p>I'm using this control in popupextender to be displayed. Each time dropdownlist postback popupcontrol disappears. Please help me with that</p>
  
  <pre><code>&lt;asp:Panel ID="pnlhotelsearch" runat="server"&gt;
  
              &lt;div&gt;
  
              &lt;/div&gt;
              &lt;uc1:SlimMainsearchpanel ID="SlimMainsearchpanel1" runat="server" /&gt;
  
  
          &lt;/asp:Panel&gt;
          &lt;ajaxToolkit:PopupControlExtender ID="PopupControlExtender1" TargetControlID="lnkbtnCriteriea" PopupControlID="pnlhotelsearch" runat="server"&gt;
          &lt;/ajaxToolkit:PopupControlExtender&gt;
  </code></pre>