title: ASPxPopup doesnt update on ASPxGridView Selection changed
body: <p>I have an ASPxPopupControl and an ASPxGridView.
  Inside this PopupControl i have my own usercontrol which contains a form for editing person information. 
  Inside the GridView is a list with different persons. 
  When i select a different person in the gridview i want the content of the popupcontrol to update for the to the person information of the selected user so i can edit it.</p>
  
  <p>My problem is; i can't get this to work, i have tried placing update panels with all sorts of triggers or forcing the updatepanel to update. But it still doesn't work.</p>
  
  <p>PopupControl:</p>
  
  <pre><code>&lt;dx:ASPxPopupControl ID="pcVolgnummerToevoegen" runat="server" AllowDragging="True" ClientInstanceName="popup_toevoegen" CloseAction="CloseButton" LoadingPanelText="Laden&amp;amp;hellip;" Height="700" Width="700" Modal="True" PopupHorizontalAlign="WindowCenter" PopupVerticalAlign="WindowCenter"&gt;
  &lt;ContentCollection&gt;
  &lt;dx:PopupControlContentControl ID="pcVolgnummerToevoegenContent" runat="server"&gt;
    &lt;asp:UpdatePanel ID="upnlToevoegen" runat="server" UpdateMode="Conditional"&gt;
      &lt;ContentTemplate&gt;
        &lt;uc:GegevensControl ID="ucGegevensControl_Toevoegen" runat="server" /&gt;
      &lt;/ContentTemplate&gt;
      &lt;Triggers&gt;
        &lt;asp:AsyncPostBackTrigger ControlID="KlantVolgnummerGrid" /&gt;
      &lt;/Triggers&gt;
    &lt;/asp:UpdatePanel&gt;
  &lt;/dx:PopupControlContentControl&gt;
  &lt;/ContentCollection&gt;
  &lt;/dx:ASPxPopupControl&gt;
  </code></pre>
  
  <p>DataView Selection_Changed:</p>
  
  <pre><code>protected void KlantVolgnummerGrid_SelectionChanged(object sender, EventArgs e)
  {
    Session["Person_Id"] = KlantVolgnummerGrid.GetSelectedFieldValues("ID");
  }
  </code></pre>
  
  <p>Page_Load of the usercontrol inside the popup</p>
  
  <pre><code>protected void Page_Load(object sender, EventArgs e)
  {
   Person varPerson = PersonControllerClient.GetPerson(Session["Person_Id"]);
   ....Code that fills the form
  }
  </code></pre>
  
  <p>I have checked the SelectionChanged event of the GridView, it triggers. But the update panel doesn't update.
  After i refresh the page the person i have selected is shown inside the popup.</p>
  
  <p>Is there anyway i can update the popup for showing the right person without having to refresh the page everytime i select a different person?</p>