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  accesswindow                                                          WNDWC
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  Function       Randomly accesses a covered window and places it on the top.
                 If the window is hidden, it uses showwindow to put it on
                 top.
  Syntax         void accesswindow( int windowname );
  Remarks        All underlays are properly updated in the heap with a high
                 speed technique.  If NOACCESSMODE has been set for this
                 window or an invalid window name is used, the function is
                 simply ignored.  Virtual windows are updated after being
                 shown.  Zoom effect is optional.  The wndwstat array is
                 shuffled to match the new levels.
  Return value   None.
  Screens        All video pages.
  EOS            Restored to new window.
  Restrictions   Shadows are permitted, but exposed corners on lower level
                 windows with shadows will not be updated until moved.  For
                 human factors, shadows are only recommended for the top
                 window anyway.
  Heap           Temporarily uses (underlay size * 1.5).
  Upon return    Forced to write to CRT.