18. SELECTED QUARTERLY CONSOLIDATED FINANCIAL DATA (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	May. 31, 2015	Feb. 28, 2015	Nov. 30, 2014	Aug. 31, 2014	May. 31, 2014	Feb. 28, 2014	Nov. 30, 2013	Aug. 31, 2013	May. 31, 2015	May. 31, 2014	May. 31, 2013
Selected Quarterly Consolidated Financial Data Details
Net sales	$ 1,818	$ 2,027	$ 2,615	$ 3,558	$ 5,370	$ 5,612	$ 4,950	$ 3,752	$ 10,018	$ 19,684	$ 16,488
Gross profit	682	852	694	1,610	2,914	2,870	2,494	1,944	3,838	10,222	6,776
Net (loss) income	$ (1,900)	$ (1,726)	$ (2,114)	$ (907)	$ 239	$ 212	$ 137	$ (166)	$ (6,647)	$ 422	$ (3,419)
Net (loss) income per share basic and diluted	$ (0.15)	$ (0.14)	$ (0.18)	$ (0.08)	$ 0.02	$ 0.02	$ 0.01	$ (0.02)	$ (0.55)	$ 0.04	$ (0.36)