Geographic Information (Tables)

3 Months Ended

Aug. 31, 2016

Geographic Information Disclosure [Abstract]

Revenue from External Customers by Geographic Areas [Table Text Block]

	Three Months Ended August 31,
	2016		2015
Revenues from sales to unaffiliated customers:
United States	$	226,000	$	187,000
Asia		575,000		433,000
Europe		554,000		619,000
South America		16,000		17,000
Middle East		38,000		31,000
Other		1,000		--
	$	1,410,000	$	1,287,000