How to attach docking windows into the TabbedMDI manager during application startup in WinForms Docking Manager?

//Creates a new panel control
Panel p=new Panel();
p.Name="New Panel";
//Enables docking for panel
this.dockingManager1.SetEnableDocking(p,true);
//Sets dock lable
this.dockingManager1.SetDockLabel(p,"New Panel");
//Changes docking window to MDI child window
this.dockingManager1.SetAsMDIChild(p,true);
//Attach MDI container to TabbedMDI manager
this.tm=new TabbedMDIManager();
this.tm.TabControlAdded+=new TabbedMDITabControlEventHandler(tm_TabControlAdded);
//Assign the MDI form into the TabbedManager MDI container.
this.tm.AttachToMdiContainer(this);
//Enable the rendering for the Tabed mdi manager tabs
private void tm_TabControlAdded(object sender, TabbedMDITabControlEventArgs args)
{
   args.TabControl.TabStyle=typeof(Syncfusion.Windows.Forms.Tools.TabRendererDockingWhidbey);
}

'Creates a new panel control
Dim p As Panel = New Panel()
p.Name="New Panel"
'Enables docking for panel
Me.dockingManager1.SetEnableDocking(p,True)
'Sets dock lable
Me.dockingManager1.SetDockLabel(p,"New Panel")
'Changes docking window to MDI child window
Me.dockingManager1.SetAsMDIChild(p,True)
'Attach MDI container to TabbedMDI manager
Me.tm = New TabbedMDIManager()
AddHandler tm.TabControlAdded, AddressOf tm_TabControlAdded
'Assign the MDI form into the TabbedManager MDI container.
Me.tm.AttachToMdiContainer(Me)
'Enable the rendering for the Tabed mdi manager tabs
Private Sub tm_TabControlAdded(ByVal sender As Object, ByVal args As TabbedMDITabControlEventArgs)
   args.TabControl.TabStyle=GetType(Syncfusion.Windows.Forms.Tools.TabRendererDockingWhidbey)
End Sub