status.i4.v = window_extrema_row_numbers_c(window_id.i2.v,
						   min_row.i4.r [,max_row.i4.r])

	This routine returns the minimum and maximum row numbers in a window.
	scroll buffer.  A value of NULL can be passed for either of the
	returned row number arguments if that value is not needed.

	window_id	window ID (use WMNGR_BACKGROUND for background window)
	min_row		returned minimum row number
	[max_row]	returned maximum row number
			(default is NULL)

	This function returns status values as follows:

	OK			success
	CBS_INVARG		invalid window ID
	CBS_NO_WINDOW		requested window does not exist
	CBS_MEMFAIL		dynamic memory allocation failure

	This function requires the following include files:

	cbslib_h, acnet_errors_h

	Related functions:

	window_total_lines_c, window_query_scroll(_c), window_scroll_offset_c,
	window_last_scroll, window_set_scroll_region_c, window_scroll(_c),
	window_scroll_page_c, window_scroll_to_top_c, window_scroll_to_bottom_c,

	C/C++ usage:

	short	window_id;
	int	status;
	int	min_row;
	int	max_row;

	status = window_extrema_row_numbers_c(window_id,&min_row,&max_row);