Stage 3: Adding the TabWorkspace

1. Open the file ShellForm.cs
2. drag a SplitContainer control onto the form.
3. Right-click the Toolbox, click "Items..." and "Browse..."
4. select the file Microsoft.Practices.CompositeUI.WinForms.dll.
5. Drag a TabWorkspace onto the left-hand panel of the SplitContainer.
6. Set Dock property to Fill.