cannot do load on demand RadTabStrip that loads user control

[EJ]

i keep getting this error

Microsoft JScript runtime error: 'get_postBackElement().id' is null or not an object

when I click on the second or third tab

when I try to implement the load on demand radtabstrip demo

i am using 2010.1 519 version of the controls

the demo seems to say this should work - is this a bug?

aspx page

<telerik:RadAjaxLoadingPanel ID="RadAjaxLoadingPanel1" runat="server">
    </telerik:RadAjaxLoadingPanel>
    <telerik:RadAjaxManager ID="RadAjaxManager1" runat="server">
        <AjaxSettings>
            <telerik:AjaxSetting AjaxControlID="RadTabStrip1">
                <UpdatedControls>
                    <telerik:AjaxUpdatedControl ControlID="RadTabStrip1" />
                    <telerik:AjaxUpdatedControl ControlID="RadMultiPage1" />
                </UpdatedControls>
            </telerik:AjaxSetting>
            <telerik:AjaxSetting AjaxControlID="RadMultiPage1">
                <UpdatedControls>
                    <telerik:AjaxUpdatedControl ControlID="RadMultiPage1" LoadingPanelID="RadAjaxLoadingPanel1" />
                </UpdatedControls>
            </telerik:AjaxSetting>
        </AjaxSettings>
    </telerik:RadAjaxManager>
    <script type="text/javascript">
        function onTabSelecting(sender, args) {
            var foo = args.get_tab();
            if (args.get_tab().get_pageViewID()) {
                args.get_tab().set_postBack(false);
            }
        }
    </script>
                    <telerik:RadTabStrip ID="RadTabStrip1" runat="server" SelectedIndex="0"
                        MultiPageID="RadMultiPage1" Orientation="HorizontalTop"
                        OnTabClick="RadTabStrip1_TabClick" OnClientTabSelecting="onTabSelecting">
                    </telerik:RadTabStrip>
                    <telerik:RadMultiPage runat="server" ID="RadMultiPage1" SelectedIndex="0"
                        Height="250px" Width="475px" BorderWidth="1" OnPageViewCreated="RadMultiPage1_PageViewCreated">
                    </telerik:RadMultiPage>

code behind

 protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            AddTab(RadTabStrip1, "Tab1");
            AddPageView(RadMultiPage1, RadTabStrip1.FindTabByText("Tab1"));
            AddTab(RadTabStrip1, "Tab2");
            //AddPageView(RadMultiPage1, RadTabStrip1.FindTabByText("Tab2"));
            AddTab(RadTabStrip1, "Tab3");
            //AddPageView(RadMultiPage1, RadTabStrip1.FindTabByText("Tab3"));
        }
    }

    private void AddTab(RadTabStrip tabstrip, string tabName)
    {
        RadTab tab = new RadTab();
        tab.Text = tabName;
        tabstrip.Tabs.Add(tab);
    }

    private void AddPageView(RadMultiPage multipage, RadTab tab)
    {
        RadPageView pageView = new RadPageView();
        pageView.ID = tab.Text;
        multipage.PageViews.Add(pageView);
        tab.PageViewID = pageView.ID;
    }

    protected void RadTabStrip1_TabClick(object sender, RadTabStripEventArgs e)
    {
        AddPageView(RadMultiPage1, e.Tab);
        e.Tab.PageView.Selected = true;
    }

    protected void RadMultiPage1_PageViewCreated(object sender, RadMultiPageEventArgs e)
    {
        string userControlPath = "~/WebUserControl.ascx";

        Control userControl = Page.LoadControl(userControlPath);
        if (e.PageView.ID == "Tab1")
        {
            userControl.ID = "UserControl1";
        }
        else if (e.PageView.ID == "Tab2")
        {
            userControl.ID = "UserControl2";
        }
        else if (e.PageView.ID == "Tab3")
        {
            userControl.ID = "UserControl3";
        }

        e.PageView.Controls.Add(userControl);
    }

[Yana]

Hi EJ,

I've just answered to the support ticket regarding this issue. Here is my reply:

I've tested the provided project but wasn't able to reproduce the described issue. Could you please send us the exact steps? Does the error occur every time you click a tab?

Best regards,
Yana
the Telerik team