CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Deficit
Balance (in shares) at Apr. 30, 2020		12,726,728
Balance (in shares) at Apr. 30, 2020
Balance at Apr. 30, 2020	$ 5,099	$ 13		$ 77,978	$ (72,892)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	598			598
Issuance of common stock on exercise of stock options and warrants (in shares)		687,338
Issuance of common stock on exercise of stock options	1,369			1,369
Net income	$ 362				362
Balance (in shares) at Apr. 30, 2021	13,414,066	13,414,066
Balance (in shares) at Apr. 30, 2021			0
Balance at Apr. 30, 2021	$ 7,428	$ 13	$ 0	79,945	(72,530)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	912			912
Issuance of common stock on exercise of stock options and warrants (in shares)		108,375
Issuance of common stock on exercise of stock options	208	$ 1		207
Net income	$ 548				548
Balance (in shares) at Apr. 30, 2022	13,522,441	13,522,441
Balance (in shares) at Apr. 30, 2022			0
Balance at Apr. 30, 2022	$ 9,096	$ 14	$ 0	$ 81,064	$ (71,982)