status.i4.v = wn_blank_c(x.r4.v, y.r4.v, num_chars.i4.v)

	This routine draws a blank text string at virtual coordinates X,Y
	in a graphics window specified by a previous call to wn_active(_c).
	wn_view(_c) and wn_world(_c) must also be called before calling
	this routine.

	x, y		real world coordinates of lower left hand
			corner of text string  (If text character scaling
			is selected with a call to wn_text_scaling_c,
			the following special coordinate values are supported.
			A value of WN_CENTER_IT for either coordinate will
			center the text relative to the active window for that
			plane.  A value of WN_JUSTIFY_MIN or WN_JUSTIFY_MAX
			will align the text to the minimum or maximum
			respectively of the corresponding axis.)
	num_chars	length of blank text string

	This function returns ACNET status values as follows:

	OK			success
	CBS_INVARG		invalid number of characters passed
	CBS_NOSETUP		an active window has not been established

	This function requires the following include files:

	cbslib_h, acnet_errors_h

	Related functions:

	wn_text(_c), wn_color(_c), wn_text_size(_c), wn_text_rotation(_c),
	wn_text_attributes_c, wn_text_scaling_c, wn_display_value(_c),
	wn_external_text(_c), wn_colored_text_c, wn_external_colored_text_c,
	wn_external_display_value_c, wn_read_text_format,
	wn_set_background_format_c, wn_read_background_format, wn_flush,

	C/C++ usage:

	int	status;
	int	num_chars = 4;
	float	x = 1.0;
	float	y = 1.0;

	status = wn_blank_c(x,y,num_chars);