Loss Per Share (Schedule Of Earnings (Loss) Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Jul. 31, 2014	Jul. 31, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net loss	$ (247)	$ (633)
Dividends paid and payable on preferred stock		(66)
Net loss available to common stockholders	$ (247)	$ (699)
Weighted-average shares of common stock outstanding, basic	16,384,000	15,297,000
Weighted-average shares of common stock outstanding, diluted	16,384,000	15,297,000
Basic	$ (0.02)	$ (0.05)
Diluted	$ (0.02)	$ (0.05)
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of antidilutive securities	1,091	1,695
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of antidilutive securities	719	909
Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of antidilutive securities		1,111