The diagram window is the main working area of the application. It displays the active diagram content. You can open multiple diagrams and switch between them using Window submenu. Also you can dispose a number of diagrams at the working area. Please note that more than one diagram can be active.
To change diagrams disposition in the working area automatically, use the following menu items:
Window | Cascade
To close all opened diagrams, use the Window | Close All menu item.