CONDENSED CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($)	Aug. 31, 2018	May 31, 2018
Allowance for doubtful accounts (in Dollars)	$ 63,392	$ 57,695
Accumulated depreciation and amortization (in Dollars)	$ 1,688,423	$ 1,661,128
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	8,953,832	8,888,011
Common stock, shares outstanding	8,953,832	8,888,011