UNAUDITED CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning balance (shares) at Apr. 30, 2018		11,003,228	269,685
Beginning balance at Apr. 30, 2018	$ 3	$ 11	$ (1,252)	$ 72,070	$ (70,826)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	75			75
Issuance of common stock for services (in shares)		4,762
Issuance of common stock on exercise of stock options (in shares)		20,000
Issuance of common stock on exercise of stock options				42
Net income (loss)	482				482
Ending balance (shares) at Jul. 31, 2018		11,027,990	269,685
Ending balance at Jul. 31, 2018	602	$ 11	$ (1,252)	72,187	(70,344)
Beginning balance (shares) at Apr. 30, 2019		11,619,538	0
Beginning balance at Apr. 30, 2019	2,238	$ 12	$ 0	72,924	(70,698)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	131			131
Net income (loss)	(641)				(641)
Ending balance (shares) at Jul. 31, 2019		11,619,538	0
Ending balance at Jul. 31, 2019	$ 1,728	$ 12	$ 0	$ 73,055	$ (71,339)