occluding.i4.v = window_is_occluding_c(window_id.i2.v

	This routine returns a value of TRUE if the window indicated by
	"window_id" is (partially or completely) occluding another window.

	window_id	window ID
	window_id_2	ID of possibly occluded window (Note: If this
			argument is not specified, this routine will
			check to see if the first window occludes any
			other window.) (default is WMNGR_INVALID_ID)

	This function returns status values as follows:

	CBS_INVARG		invalid window ID
	CBS_NO_WINDOW		no such window
	CBS_MEMFAIL		dynamic memory allocation failure
	TRUE			first window is occluding another window
	FALSE			first window is not occluding another window

	This function requires the following include files:

	cnsparam_h, cbslib_h, acnet_errors_h

	Related functions:

	window_occluded_c, window_occluded_by_c, window_occluding_c,
	window_intersect_c, intro_tv_windows

	C/C++ usage:

	short	window_id;
	short	window_id_2;
	int	occluding;

	occluding = window_is_occluding_c(window_id,window_id_2);