Closing of all outputwindows.
close_all_windows closes all windows which had been opened by open_window or by open_textwindow. Afterwards the output device resp. the window area are ready to accept new calls of open_window and of open_textwindow.
After the call of close_all_windows you have to call once more a procedure to open a new window, if you want to perform other display output.
close_all_windows(:::).
If at least one ouputwindow exists, then close_all_windows returns TRUE. If necessary an exception is raised.
open_window, open_textwindow, set_window
open_window, open_textwindow, set_window