Derivative Liabilities (Tables)

6 Months Ended

Jan. 31, 2013

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule Of Derivative Warrant Liability [Table Text Block]

The following summarizes the changes in the value of the derivative warrant liability from August 1, 2011 until January 31, 2013:

	Value			No. of Warrants
Balance at August 1, 2011 – Derivative warrant liability	$	8,745,508			80,234,017
Exercise of warrants classified as derivative liability		(7,230,734	)		(49,863,260	)
Additional warrants issued in February 2012 financing		1,811,746			13,333,333
Additional warrants from price protection features of existing warrants		1,548,813			11,444,440
Decrease in fair value of derivative warrant liability		(793,706	)		n/a
Balance at July 31, 2012 – Derivative warrant liability	$	4,081,627			55,148,530
Additional warrants issued in August 2012 financing		624,797			9,375,000
Additional warrants issued in December 2012 financing		762,355			24,999,999
Additional warrants from price protection features of existing warrants		7,484,550			236,219,094
Exercise of warrants		(3,087,279	)		(109,428,097	)
Decrease in fair value of derivative warrant liability		(3,738,952	)		n/a
	$	6,127,098			216,314,526

Schedule of Derivative Liabilities at Fair Value [Table Text Block]

The key inputs used in the January 31, 2013 and July 31, 2012 fair value calculations were as follows:

	January 31, 2013			July 31, 2012
Current exercise price	$	0.03		$	0.15
Time to expiration		3.61 years			3.9 years
Risk-free interest rate		0.65	%		0.45	%
Estimated volatility		84	%		104	%
Dividend		-0-			-0-
Stock price at period end date	$	0.045		$	0.093