Toggle Between One and Two Windows

  The Change Window Mode key controls the number of windows
  displayed on the screen.  If the screen has one window, this
  key creates a second window and places the cursor in the newly
  created window.  If the screen has two or more windows, the Change
  Window Mode key removes the multiple windows and displays the
  current buffer in the single window.

  Command Equivalent:

          CHANGE WINDOW_MODE

  Related Topics:

          DELETE WINDOW
          ONE WINDOW
 	 SET SCREEN WINDOW
          SPLIT WINDOW