Share-Based Payments (Details 2) (USD $)	3 Months Ended
	Jul. 31, 2013
Outstanding, Begining Balance	13,890,205
Granted	310,000
Forfeited	(12,500)
Expired	(26,250)
Outstanding, Ending Balance	14,161,455
Vested and expected to vest as of July 31, 2013	14,161,455
Exercisable as of July 31, 2013	12,565,704
Weighted Average Exercise Price, Outstanding, Begining Balance	$ 0.85
Weighted Average Exercise Price, Granted	$ 0.53
Weighted Average Exercise Price, Forfeited	$ 0.50
Weighted Average Exercise Price, Expired	$ 0.75
Weighted Average Exercise Price, Outstanding, Ending Balance	$ 0.85
Weighted Average Exercise Price, Vested and expected to vest	$ 0.85
Weighted Average Exercise Price, Exercisable	$ 0.85
Weighted Average Remaining Contractual Term, Outstanding, Begining Balance (in years)	7 years
Weighted Average Remaining Contractual Term, Outstanding, Ending Balance (in years)	6 years 9 months 18 days
Vested and expected to vest as of July 31, 2013(in Years)	6 years 9 months 18 days
Weighted Average Remaining Contractual Term, Exercisable (in years)	6 years 8 months 12 days
Aggregate Intrinsic Value, Outstanding, Begining Balance	$ 89,000
Aggregate Intrinsic Value, Outstanding, Ending Balance	3,062,000
Aggregate Intrinsic Value, Vested and expected to vest	3,062,000
Aggregate Intrinsic Value, Exercisable	$ 2,703,000
Non-Employees [Member]
Outstanding, Begining Balance	765,000
Granted	0
Forfeited	0
Expired	0
Outstanding, Ending Balance	765,000
Vested and expected to vest as of July 31, 2013	765,000
Exercisable as of July 31, 2013	488,334
Directors and Employees [Member]
Outstanding, Begining Balance	13,125,205
Granted	310,000
Forfeited	(12,500)
Expired	(26,250)
Outstanding, Ending Balance	13,396,455
Vested and expected to vest as of July 31, 2013	13,396,455
Exercisable as of July 31, 2013	12,077,370