Note 7 - Net Income (Loss) per Share (Details) - Schedule of Earnings Per Share, Basic and Diluted - USD ($)	3 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Basic net income (loss) per share computation:
Net income(loss)	$ 257,776	$ (746,073)
Preferred dividends	(80,000)	(60,000)
Diluted income (loss)	$ 177,776	$ (806,073)
Weighted-average common shares outstanding (in Shares)	3,255,887	3,255,887
Incremental shares attributable to the assumed exercise of outstanding stock options and warrants (in Shares)	155,531	0
Total adjusted weighted-average shares (in Shares)	3,411,418	3,255,887
Diluted net income (loss) per share (in Dollars per share)	$ 0.05	$ (0.25)
Net loss attributable to common shareholders	$ 177,776	$ (806,073)
Basic net income (loss) per share (in Dollars per share)	$ 0.05	$ (0.25)