+ The first four functions get and set those windows. It is not
+ necessary to set either window; by default, the driver code uses <B>stdscr</B>
+ for both.
+
+ In the <B>set_</B> functions, window argument of <B>NULL</B> is treated as though it
+ were <B>stsdcr</B>. A menu argument of <B>NULL</B> is treated as a request to change
+ the system default menu window or subwindow.
+
+ The function <B>scale_menu</B> returns the minimum size required for the
+ subwindow of <I>menu</I>.