window_id.i4.v = wn_find_id(x.i4.r, y.i4.r)

	window_id.i4.v = wn_find_id_c(x.i4.v, y.i4.v)

	This routine returns the window ID that includes the pixel
	coordinates passed as arguments.  If the pixel coordinates are
	in more than one window, a value of CBS_DUPREQ is returned.
	In this case, a call to wn_find_list_c will return the list of
	window IDs in which this location was found.

	x, y		pixel coordinates of interest

	This function returns status values as follows:

	CBS_NO_SUCH		point is not in any window
	CBS_DUPREQ		point is in more than one window
	otherwise		ID of window including point

	This function requires the following include files:

	cbslib_h, acnet_errors_h

	Related functions:

	wn_find_list_c, wn_view(_c), wn_cursor_update, intro_graphics_windows

	C/C++ usage:

	int	window_id;
	int	x = 320;
	int	y = 256;

	window_id = wn_find_id_c(x,y);