CONDENSED CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($)	Feb. 28, 2021	May 31, 2020
Allowance for doubtful accounts (in Dollars)	$ 649,419	$ 70,981
Accumulated depreciation and amortization (in Dollars)	1,945,908	1,867,643
Accumulated amortization, Right of Use Assets (in Dollars)	405,407	231,489
Accumulated amortization, Intangible Assets (in Dollars)	$ 517,792	$ 496,124
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	12,302,157	11,740,089
Common stock, shares outstanding	12,302,157	11,740,089
5% Percent 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	321,429
Preferred Stock, shares outstanding	0	321,429
Preferred Stock [Member]
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