did_it.i4.v = window_hline_c(window_id.i2.v, row.i4.v, left_column.i4.v,
				     num_columns.i4.v, color.i4.v
				     [,ends.i4.v] [,style.i4.v] [,options.u4.v])

	This routine draws a horizontal line in the window indicated by
	"window_id" starting at "row", "column" and having a length of
	"num_columns" characters.

	window_id	window ID (use WMNGR_BACKGROUND for background window)
	row		row of line
	left_column	column of left end of line
	num_columns	length of line in columns
	color		color of line (constants are in 'cnsparam')
	[ends]		optional argument which if specified will place
			end characters at either end of the line
			(WMNGR_NO_ENDS -> no special ends (default),
			 WMNGR_TEES -> use tees as end characters,
			 WMNGR_TOP_CORNERS -> use top corners,
			 WMNGR_BOT_CORNERS -> use bottom corners)
			(If you want ends that join with the right hand
			 border of the window, you must turn off clipping
			 for that window.)
	[style]		(WMNGR_THIN_LINE -> thin line (default),
			 WMNGR_THICK_LINE -> thick line)
	[options]	options mask (values can be logically ORed together)
			(WMNGR_OPT_INTERSECT_LINES -> preserve line
			(default is WMNGR_OPT_NONE)

	This function returns status values as follows:

	CBS_INVARG		invalid end character or line style passed
	TRUE			window I/O actually done
	FALSE			no window I/O done

	This function requires the following include files:

	cnsparam_h, cbslib_h, acnet_errors_h

	Related functions:

	window_vline_c, window_box_c, window_set_clip_c,
	window_set_parameter_c, intro_tv_windows

	C/C++ usage:

	short	window_id;
	int	did_it;
	int	row = 1;
	int	left_column = 1;
	int	num_columns = 10;
	int	color = WHITE;
	int	ends = WMNGR_NO_ENDS;
	int	style = WMNGR_THIN_LINE;
	unsigned int	options = WMNGR_OPT_NONE;

	did_it = window_hline_c(window_id,row,left_column,num_columns,