<oWndClient>              Exported, TMDICLIENT object, user
------------------------------------------------------------------------------


  Contains the object of the MDI Client Window that represents a frameless
  inner window that is automatically created for every MDI frame window.
  This Client Window is sized to the entire usable internal Area of the 
  MDI-Frame, think of it as a Window inside a Window. 
  A reference to this Client Window is stored in this InstanceVar