vdata_id	IN:	Vdata identifier returned by VSattach
	interlace_mode	OUT:	Interlace mode

	Purpose	Retrieves the interlace mode of the vdata.
	Return value	Returns SUCCEED (or 0) if successful and FAIL (or -1) otherwise.
	Description	VSQueryinterlace retrieves the interlace mode of the vdata identified by the parameter vdata_id into the parameter interlace_mode.
		Valid values for interlace_mode are FULL_INTERLACE (or 0) and NO_INTERLACE (or 1).

	FORTRAN	integer function vsqfintr(vdata_id, interlace_mode)
		integer vdata_id, interlace_mode