Note 7 - Net Income (Loss) per Share (Details) - Schedule of Earnings Per Share, Basic and Diluted - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Basic net income (loss) per share computation:
Net income (loss)	$ 536,234	$ (191,410)	$ 794,010	$ (937,483)
Preferred dividends	(80,000)	(60,000)	(160,000)	(120,000)
Net income (loss) attributable to common shareholders	456,234	(251,410)	634,010	(1,057,483)
Preferred dividends	80,000		160,000
Diluted income (loss) attributable to common shareholders	$ 536,234	$ (251,410)	$ 794,010	$ (1,057,483)
Weighted-average common shares outstanding (in Shares)	3,255,887	3,255,887	3,255,887	3,255,887
Incremental shares attributable to the assumed exercise of preferred stock, outstanding stock options and warrants (in Shares)	1,689,778		1,689,778
Total adjusted weighted-average shares (in Shares)	4,945,665	3,255,887	4,945,665	3,255,887
Diluted net income (loss) per share (in Dollars per share)	$ 0.11	$ (0.08)	$ 0.16	$ (0.32)
Basic net income (loss) per share (in Dollars per share)	$ 0.14	$ (0.08)	$ 0.19	$ (0.32)