Share-Based Payments (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Jul. 31, 2012
Outstanding, Beginning	14,866,038
Granted	251,250
Exercised	0
Forfeited	0
Expired	(13,333)
Change in employee status	0
Outstanding, Ending	15,103,955
Vested and expected to vest	15,103,955
Exercisable	8,960,010
Weighted Average Exercise Price Outstanding, Beginning	$ 0.88
Weighted Average Exercise Price Granted	$ 0.57
Weighted Average Exercise Price Exercised	$ 0
Weighted Average Exercise Price Forfeited	$ 0
Weighted Average Exercise Price Expired	$ 0.95
Weighted Average Exercise Price Change in employee status	$ 0
Weighted Average Exercise Price Outstanding, Ending	$ 0.87
Weighted Average Exercise Price Vested and expected to vest	$ 0.87
Weighted Average Exercise Price Exercisable	$ 0.88
Weighted Average Remaining Contractual Term, Outstanding, Beginning	7 years 7 months 6 days
Weighted Average Remaining Contractual Term Outstanding, Ending	7 years 4 months 24 days
Weighted Average Remaining Contractual Term Vested and expected to vest	7 years 4 months 24 days
Weighted Average Remaining Contractual Term Exercisable	6 years 8 months 12 days
Aggregate Intrinsic Value Outstanding, Beginning	$ 0
Aggregate Intrinsic Value Outstanding, Ending	0
Aggregate Intrinsic Value Vested and expected to vest	0
Aggregate Intrinsic Value Exercisable	$ 0
Non- Employees [Member]
Outstanding, Beginning	1,410,000
Granted	15,000
Exercised	0
Forfeited	0
Expired	0
Change in employee status	0
Outstanding, Ending	1,425,000
Vested and expected to vest	1,425,000
Exercisable	1,248,333
Directors and Employees [Member]
Outstanding, Beginning	13,456,038
Granted	236,250
Exercised	0
Forfeited	0
Expired	(13,333)
Change in employee status	0
Outstanding, Ending	13,678,955
Vested and expected to vest	13,678,955
Exercisable	7,711,677