CONDENSED CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($)	Nov. 30, 2019	May 31, 2019
Allowance for doubtful accounts (in Dollars)	$ 76,681	$ 73,110
Accumulated depreciation and amortization (in Dollars)	$ 1,813,925	$ 1,762,344
Preferred Stock, No Par Value (in Dollars per share)	$ 0	$ 0
Preferred Stock, shares authorized	5,000,000	5,000,000
Preferred Stock, shares issued	0	0
Preferred Stock, shares outstanding	0	0
Common stock par value (in Dollars per share)	$ 0.08	$ 0.08
Common stock, shares authorized	25,000,000	25,000,000
Common stock, shares issued	9,851,090	9,677,188
Common stock, shares outstanding	9,851,090	9,677,188