[Solved] Cannot create Treeview inside a Panelbar

[Gini]

When I put a treeview inside a panel, I got this error:
Cannot convert lambda expression to type 'string' because it is not a delegate type. 

<% Html.Telerik().PanelBar()
           .Name("PanelBar")
           .HtmlAttributes(new { style = "width: 300px; float: left; margin-bottom: 30px;" })
           .ExpandMode((PanelBarExpandMode)Enum.Parse(typeof(PanelBarExpandMode), (string)ViewData["expandMode"]))
           .SelectedIndex(0)
           .Items(item =>
           {
               item.Add()
                   .Text("Mail")
                   .Content(() =>
                   {Html.Telerik().TreeView()
                                .Name("TreeView")
                                .Items(item =>
                                {
                                    item.Add()
                                        .Text("Mail")
                                        .Items(subItem =>
                                        {
                                            subItem.Add()
                                                   .Text("Personal Folders");

                                            subItem.Add()
                                                   .Text("Deleted Items");

                                            subItem.Add()
                                                   .Text("Inbox");

                                            subItem.Add()
                                                   .Text("My Mail");

                                            subItem.Add()
                                                   .Text("Sent Items");

                                            subItem.Add()
                                                   .Text("Outbox");

                                            subItem.Add()
                                                   .Text("Search Folders");
                                        });
                                }).Render();});

           })
           .Render();
       %>

[Jason]

Not sure this helps but I wrapped my content in html and placed the tree view inside <% ..  %> tags and it worked.

<% Html.Telerik().PanelBar()
       .Name("PanelBar")

       .HtmlAttributes(new { style = "width: 170px; float: left; margin-bottom: 10px;" })
       .ExpandMode(PanelBarExpandMode.Single)
       .SelectedIndex(0)
       .Items(item =>
           {
               item.Add()
                   .Text("Businesses")
                   .Content(() =>
                {
                %>
                   <%= Html.Telerik().TreeView()
                       .Name("Companies")
                       .ShowCheckBox(true)
                       .BindTo(Model.ContextViewModels[0].Companies, mappings =>
                       {