2. STOCK-BASED COMPENSATION (Details Narrative) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Aug. 31, 2014	Aug. 31, 2013
Stock-based compensation costs capitalized as part of inventory	$ 51	$ 0
Stock-based compensation expense related to stock options	162	134
Intrinsic value of options exercised	407	43
Weighted average remaining contractual life of the options exercisable and expected to be exercisable	4 years 9 months 4 days
Employee Stock Purchase Plan
Stock-based compensation related to the ESPP	35	9
Compensation cost related to options to purchase the Company's common stock under the ESPP but not yet recognized	74
Weighted average period for recognition of costs for ESPP	10 months 24 days
1996 Stock Option Plan and 2006 Equity Incentive Plan
Unrecognized stock-based compensation	1,781
Estimated forfeitures of unvested stock based awards	$ 4
Weighted average remaining period of the underlying options	3 years