CONDENSED CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($)	Aug. 31, 2021	May 31, 2021
Allowance for doubtful accounts (in Dollars)	$ 742,524	$ 837,415
Accumulated depreciation and amortization (in Dollars)	2,000,167	1,972,357
Accumulated amortization, Right of Use Assets (in Dollars)	531,974	469,077
Accumulated amortization, Intangible Assets (in Dollars)	$ 83,683	$ 126,769
Preferred Stock, shares issued	0	0
Preferred Stock, shares outstanding	0	0
Preferred Stock, No Par Value (in Dollars per share)	$ 0	$ 0
Preferred Stock, undesignated shares	4,428,571	4,428,571
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	12,510,210	12,307,157
Common stock, shares outstanding	12,510,210	12,307,157
5% Convertible Preferred Stock [Member] | Series A Preferred Stock [Member]
Preferred Stock, Par Value (in Dollars per share)	$ 0.08	$ 0.08
Preferred Stock, shares authorized	571,429	571,429
Preferred Stock, shares issued	0	0
Preferred Stock, shares outstanding	0	0