Schedule of Warrant Liabilities at Fair Value (Details) (USD $)	6 Months Ended
	Oct. 31, 2012
Derivative Instruments And Fair Value Measurement Schedule Of Warrant Liabilities At Fair Value 1	$ 1,311,141
Derivative Instruments And Fair Value Measurement Schedule Of Warrant Liabilities At Fair Value 2	715,803
Derivative Instruments And Fair Value Measurement Schedule Of Warrant Liabilities At Fair Value 3	2,026,944
Derivative Instruments And Fair Value Measurement Schedule Of Warrant Liabilities At Fair Value 4	(927,703)
Derivative Instruments And Fair Value Measurement Schedule Of Warrant Liabilities At Fair Value 5	(129,790)
Derivative Instruments And Fair Value Measurement Schedule Of Warrant Liabilities At Fair Value 6	$ 969,451