Changes in value of derivative warrant liability - Derivative Liabilities (Details) (USD $)	12 Months Ended		24 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2014
Balance - Derivative warrant liability Value				$ 2,635,643
No. of Warrants - Derivative warrant liability				257,331,254
Exercise of Warrants		(5,629,130)	(2,194,496)
Warrants Exercised		(145,888,421)	(76,732,020)
Decrease in fair value of derivative warrant liability	(3,279,650)	(3,279,650)	(3,362,497)
August 2012
Balance - Derivative warrant liability Value				4,081,627
No. of Warrants - Derivative warrant liability				55,148,530
Additional warrants issued	624,797
Warrants Issued	9,375,000
December 2012
Additional warrants issued	762,355
Warrants Issued	24,999,999
June 2013
Additional warrants issued	1,189,744
Warrants Issued	40,833,335
July 2013
Balance - Derivative warrant liability Value				5,234,293
No. of Warrants - Derivative warrant liability				220,687,537
Price Protection
Additional warrants issued		7,484,550
Warrants Issued		236,219,094
January 2014
Additional warrants issued	942,279
Warrants Issued	26,666,668
March 2014
Additional warrants issued	$ 2,016,064
Warrants Issued	69,166,667