Income Taxes - Income tax expense differs from expected tax expense (Details) (USD $)	12 Months Ended
	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Income Tax Disclosure [Abstract]
Federal income tax at statutory rates	$ (1,459,000)	$ (1,106,000)	$ (1,574,000)
State income taxes (net of Federal income tax benefit)	(249,000)	(193,000)	(319,000)
Other	52,000	(47,000)	(259,000)
Total income tax expense (benefit) before provision for valuation allowance	(1,656,000)	(1,346,000)	(2,152,000)
Changes in valuation allowance	1,661,000	1,351,000	2,157,000
Total income tax expense	$ 5,000	$ 5,000	$ 5,000