Stock Options and Warrants (Tables)

12 Months Ended

May 31, 2014

Estimated Fair Value of Options and Warrants is determined using Black-Scholes Option Valuation Model

The estimated fair value of options and warrants is determined using the Black-Scholes option valuation model with the following weighted-average assumptions for the periods ended May 31, 2014 and 2013:

	2014	2013
Risk free rate	0.52% - 1.85%	0.12% -   .70%
Dividend yield	—	—
Volatility	78.73% - 92.92%	87% - 102%
Expected term	2.5 – 3.5 years	1 – 4 years
Grant date fair value	$  .40 - $.67	$  .56 - $.89

Stock Option and Warrant Activity

The following table represents stock option and warrant activity for the periods ended May 31, 2014 and 2013:

	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life in Years		Aggregate Intrinsic Value
Options and warrants outstanding – May 31, 2012		10,327,664		$	1.60		3.20	$	2,308,279
Granted		11,166,274			1.61		—		—
Exercised		(780,000	)		0.26		—		—
Forfeited/expired/cancelled		(2,567,000	)		1.73		—		—
Options and warrants outstanding – May 31, 2013		18,146,938			1.65		1.86		140,321
Granted		18,414,144			0.74		—		—
Exercised		(50,000	)		—		—		—
Forfeited/expired/cancelled		(5,704,721	)		1.49		—		—
Options and warrants outstanding – May 31, 2014		30,806,361			1.13		3.29		177,042
Outstanding exercisable – May 31, 2014		29,986,581		$	1.15		3.21	$	170,042