Private Placements and Public Offerings (Tables)

9 Months Ended

12 Months Ended

Apr. 30, 2013

Jul. 31, 2012

Private Placements and Public Offerings

Schedule of derivative liabilities valued using a Monte Carlo valuation model

	March 28, 2012
Closing price per share of common stock	0.22
Exercise price per share	0.50
Expected volatility	125.0	%
Risk-free interest rate	1.05	%
Dividend yield	—
Floor price	0.50
Remaining expected term of underlying securities (years)	4.24

	March 28, 2012		July 31, 2011
Closing price per share of common stock	0.22		0.93
Exercise price per share	0.50		1.20
Expected volatility	125.0	%	91.6	%
Risk-free interest rate	1.05	%	1.35	%
Dividend yield	—		—
Floor price	0.50		0.50
Remaining expected term of underlying securities (years)	4.24		4.90