public partial class RadDockSpikeUserControl : UserControl
{
    public RadAjaxManager AjaxManager;
 
    private List<DockState> _currentDockStates
    {
        get
        {
            //Store the info about the added docks in the session. For real life  
            // applications we recommend using database or other storage medium   
            // for persisting this information.  
            List<DockState> _currentDockStates = (List<DockState>)Session["CurrentDockStatesMyPortal"];
            if (Object.Equals(_currentDockStates, null))
            {
                _currentDockStates = new List<DockState>();
                Session["CurrentDockStatesMyPortal"] = _currentDockStates;
            }
            return _currentDockStates;
        }
        set
        {
            Session["CurrentDockStatesMyPortal"] = value;
        }
    }
 
    protected override void OnInit(EventArgs e)
    {
        base.OnInit(e);
 
        // Initialize toolbar
        RadToolBarButton button = new RadToolBarButton();
        button.Text = "Open new dock";
        ToolBar.Items.Add(button);
 
        ToolBar.ButtonClick += new RadToolBarEventHandler(ToolBar_ButtonClick);
 
        //Recreate the docks in order to ensure their proper operation  
        for (int i = 0; i < _currentDockStates.Count; i++)
        {
            if (_currentDockStates[i].Closed == false)
            {
                AddDockFromState(_currentDockStates[i]);
                //We want to save the dock state every time a dock is moved.  
            }
        }
    }
 
    protected override void CreateChildControls()
    {
        base.CreateChildControls();
         
    }
 
    protected override void OnPreRender(EventArgs e)
    {
        base.OnPreRender(e);
        AjaxManager.AjaxSettings.AddAjaxSetting(ToolBar, Panel1, AjaxLoadingPanel);
         
    }
 
    protected void HandleLoadDockLayout(object sender, DockLayoutEventArgs e)
    {
        //Populate the event args with the state information. The RadDockLayout control  
        // will automatically move the docks according that information.  
        foreach (DockState state in _currentDockStates)
        {
            e.Positions[state.UniqueName] = state.DockZoneID;
            e.Indices[state.UniqueName] = state.Index;
        }
    }
 
    protected void HandleSaveDockLayout(object sender, DockLayoutEventArgs e)
    {
        //Save the dock state in the session. This will enable us   
        // to recreate the dock in the next Page_Init.   
        _currentDockStates = DockLayout.GetRegisteredDocksState();
    }
 
    void ToolBar_ButtonClick(object sender, RadToolBarEventArgs e)
    {
        AddDock("Untitled...");
    }
 
    private void AddDockFromState(DockState state)
    {
        RadDock dock = new RadDock();
        dock.ID = string.Format("Dock{0}", state.UniqueName);
        dock.ApplyState(state);
 
        Panel1.Controls.Add(dock);
 
        CreateSaveStateTrigger(dock);
    }
 
    protected void AddDock(string title)
    {
        RadDock dock = new RadDock();
        dock.UniqueName = Guid.NewGuid().ToString();
        dock.ID = string.Format("Dock{0}", dock.UniqueName);
        dock.Title = title;
        dock.Text = "Dock content";
        //dock.Resizable = true;
        //dock.EnableRoundedCorners = true;
 
        Panel1.Controls.Add(dock);
 
        CreateSaveStateTrigger(dock);
 
    // Here is the problem: The dock client instance is null???!!!
        string script = string.Format(@"                            
                        var dock = $find('{0}');
            alert('Dock: ' + dock);
                        //$find('{1}').dock($find('{0}'));
                        $find('{2}').ajaxRequest();",
                dock.ClientID, PageDockZone.ClientID, AjaxManager.ClientID);
 
        AjaxManager.ResponseScripts.Add(script);
 
 
    }
 
    private void CreateSaveStateTrigger(RadDock dock)
    {
        //Ensure that the RadDock control will initiate postback
        // when its position changes on the client or any of the commands is clicked.
        //Using the trigger we will "ajaxify" that postback.
        dock.AutoPostBack = true;
        dock.CommandsAutoPostBack = true;
 
        AjaxSetting trigger = new AjaxSetting();
        trigger.AjaxControlID = dock.ID;
        trigger.EventName = "DockPositionChanged";
 
        AjaxUpdatedControl updatedControl = new AjaxUpdatedControl();
        updatedControl.ControlID = Panel1.ID;
 
        trigger.UpdatedControls.Add(updatedControl);
        AjaxManager.AjaxSettings.Add(trigger);
 
 
        trigger = new AjaxSetting();
        trigger.AjaxControlID = dock.ID;
        trigger.EventName = "Command";
 
        updatedControl = new AjaxUpdatedControl();
        updatedControl.ControlID = Panel1.ID;
 
        trigger.UpdatedControls.Add(updatedControl);
        AjaxManager.AjaxSettings.Add(trigger);
    }
}
   


    

    
Usercontrol loaded by the WebPart  (RadDockSpikeUserControl.ascx):
    
    
    





<telerik:RadToolBar ID="ToolBar" runat="server">
     
</telerik:RadToolBar>
  
<asp:Panel ID="DocksContainer" runat="server">
    <telerik:RadDockLayout ID="DockLayout" runat="server" OnLoadDockLayout="HandleLoadDockLayout" OnSaveDockLayout="HandleSaveDockLayout" >    
                  
        <telerik:RadDockZone ID="PageDockZone" runat="server">
  
        </telerik:RadDockZone>
  
       <div style="display: block">
            Hidden Ajaxified asp:Panel, which is used to receive the new dock controls. We will move
            them with script to the desired initial dock zone.
            <asp:Panel ID="Panel1" runat="server">
            </asp:Panel>
        </div>
  
  
    </telerik:RadDockLayout>
</asp:Panel>
  
<telerik:RadAjaxLoadingPanel ID="AjaxLoadingPanel" runat="server" Skin="Default" MinDisplayTime="500">
</telerik:RadAjaxLoadingPanel>