4. EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Aug. 31, 2020	Aug. 31, 2019
Earnings Per Share [Abstract]
Numerator: Net income (loss)	$ 107	$ (413)
Denominator for basic net income (loss) per share: Weighted average shares outstanding (in thousands)	23,248	22,708
Shares used in basic net income (loss) per share calculation (in thousands)	23,248	22,708
Effect of dilutive securities (in thousands)	207	0
Denominator for diluted net income (loss) per share (in thousands)	23,455	22,708
Basic net income (loss) per share	$ .00	$ (.02)
Diluted net income (loss) per share	$ .00	$ (.02)