CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($)	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	$ 3,000	$ 11,000	$ (1,252,000)	$ 72,070,000	$ (70,826,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	75,000			75,000
Issuance of common stock for services (in shares)		4,762
Issuance of common stock on exercise of stock options and warrants (in shares)		20,000
Issuance of common stock on exercise of stock options and warrants				42,000
Net income	483,000				483,000
Ending balance (shares) at Jul. 31, 2018		11,027,990	269,685
Ending balance at Jul. 31, 2018	603,000	$ 11,000	$ (1,252,000)	72,187,000	(70,343,000)
Beginning balance (shares) at Apr. 30, 2018		11,003,228	269,685
Beginning balance at Apr. 30, 2018	3,000	$ 11,000	$ (1,252,000)	72,070,000	(70,826,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	381,000
Ending balance (shares) at Jan. 31, 2019		11,612,700	0
Ending balance at Jan. 31, 2019	2,323,000	$ 12,000	$ 0	72,756,000	(70,445,000)
Beginning balance (shares) at Jul. 31, 2018		11,027,990	269,685
Beginning balance at Jul. 31, 2018	603,000	$ 11,000	$ (1,252,000)	72,187,000	(70,343,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	88,000			88,000
Issuance of common stock on exercise of stock options and warrants (in shares)		446,815	269,685
Issuance of common stock on exercise of stock options and warrants	1,034,000		$ 1,252,000	(218,000)
Net income	267,000				267,000
Ending balance (shares) at Oct. 31, 2018		11,474,805	0
Ending balance at Oct. 31, 2018	1,992,000	$ 11,000	$ 0	72,057,000	(70,076,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	335,000			335,000
Issuance of common stock on exercise of stock options and warrants (in shares)		137,895
Issuance of common stock on exercise of stock options and warrants	365,000	$ 1,000		364,000
Net income	(369,000)				(369,000)
Ending balance (shares) at Jan. 31, 2019		11,612,700	0
Ending balance at Jan. 31, 2019	$ 2,323,000	$ 12,000	$ 0	$ 72,756,000	$ (70,445,000)