window_scroll(_c)

	status.i4.v = window_scroll(window_id.i2.r, direction.i4.r
				    [,num_lines.i4.r] [,limit.i4.r])

	status.i4.v = window_scroll_c(window_id.i2.v, direction.i4.v
				      [,num_lines.i4.v] [,limit.i4.v])

	Scroll the window indicated by "window_id" up or down by one or
	more lines.

	window_id	window ID (use WMNGR_BACKGROUND for background window)
	direction	scroll direction
			(WMNGR_UP -> scroll text up,
			 WMNGR_DOWN -> scroll text down)
	[num_lines]	number of lines to scroll (default is 1)
	[limit]		scroll limit flag
			(TRUE -> limit the scroll to the present scroll buffer,
			 FALSE -> don't limit scroll (default))

	This function returns ACNET status values as follows:

	OK			success
	CBS_INVARG		invalid number of lines or window ID
	CBS_NO_WINDOW		requested window does not exist
	CBS_MEMFAIL		failed in allocating dynamic memory
	CBS_TOO_MANY		scroll buffer is full

	This function requires the following include files:

	cnsparam_h, cbslib_h, acnet_errors_h

	Related functions:

	window_scroll_page_c, window_scroll_to_bottom_c,
	window_scroll_to_top_c, window_last_scroll, window_query_scroll,
	window_scroll_offset_c, window_total_lines_c,
	window_set_scroll_region_c, window_set_scroll_limit_c,
	window_entry_to_row_c, window_row_to_entry_c,
	window_hscroll_c, window_hscroll_page_c, window_set_parameter_c,
	intro_tv_windows

	C/C++ usage:

	short	window_id;
	int	status;
	int	direction = WMNGR_UP;
	int	num_lines = 1;
	int	limit = TRUE;

	status = window_scroll_c(window_id,direction,num_lines,limit);