Note 7 - Net Income (Loss) per Share (Details) - Schedule of Earnings Per Share, Basic and Diluted - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Basic net (loss) income per share computation:
Net (loss) income	$ (364,103)	$ 141,513	$ (3,570,783)	$ 823,877
Weighted-average common shares outstanding	3,255,887	3,255,887	3,255,887	3,255,887
Basic net (loss) income per share	$ (0.11)	$ 0.04	$ (1.10)	$ 0.25
Diluted net (loss) income per share computation
Net (loss) income	$ (364,103)	$ 141,513	$ (3,570,783)	$ 823,877
Add: Change in fair value of warrants	0	37,000	0	70,000
Diluted (loss) income	$ (364,103)	$ 104,513	$ (3,570,783)	$ 753,877
Weighted-average common shares outstanding	3,255,887	3,255,887	3,255,887	3,255,887
Incremental shares attributable to the assumed exercise of outstanding stock options and warrants	0	9,248	0	10,645
Total adjusted weighted-average shares	3,255,887	3,265,135	3,255,887	3,266,532
Diluted net (loss) income per share	$ (0.11)	$ 0.03	$ (1.10)	$ 0.23