3. EARNINGS PER SHARE (''EPS'') (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	May 31, 2021	Feb. 28, 2021	Nov. 30, 2020	Aug. 31, 2020	May 31, 2020	Feb. 29, 2020	Nov. 30, 2019	Aug. 31, 2019	May 31, 2021	May 31, 2020	May 31, 2019
Earnings Per Share [Abstract]
Numerator: Net income (loss)	$ 567	$ (735)	$ (1,966)	$ 107	$ (2,885)	$ 245	$ 251	$ (413)	$ (2,027)	$ (2,802)	$ (5,235)
Denominator for basic net loss per share: Weighted average shares outstanding (in thousands)									23,457	22,882	22,387
Shares used in basic net loss per share calculation (in thousands)									23,457	22,882	22,387
Effect of dilutive securities (in thousands)									0	0	0
Denominator for diluted net loss per share (in thousands)									23,457	22,882	22,387
Basic net loss per share									$ (.09)	$ (0.12)	$ (0.23)
Diluted net loss per share									$ (0.09)	$ (0.12)	$ (0.23)