3. EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 28, 2017	Feb. 29, 2016	Feb. 28, 2017	Feb. 29, 2016
Earnings Per Share [Abstract]
Numerator: Net loss	$ (2,651)	$ (2,975)	$ (4,858)	$ (3,729)
Denominator for basic net loss per share: Weighted average shares outstanding (in thousands)	16,672	13,164	15,411	13,058
Shares used in basic net loss per share calculation (in thousands)	16,672	13,164	15,411	13,058
Effect of dilutive securities (in thousands)	0	0	0	0
Denominator for diluted net loss per share (in thousands)	16,672	13,164	15,411	13,058
Basic net loss per share	$ (.16)	$ (.23)	$ (.32)	$ (.29)
Diluted net loss per share	$ (0.16)	$ (0.23)	$ (0.32)	$ (0.29)