STOCK-BASED COMPENSATION (Details 3) (Warrant [Member], USD $)									12 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2011	May 31, 2010	May 31, 2009	May 31, 2008	May 31, 2007	May 31, 2006	May 31, 2013 Range One [Member]	May 31, 2013 Range Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number, Beginning Balance	2,350,080	5,895,945	5,235,945	11,735,004	11,735,004	10,044,916	9,048,240	4,392,874	1,690,080	660,000
Share-based Compensation Arrangement by Share-based Payment Award, Non Option Equity Instruments, Outstanding, Weighted Average Exercise Price, Beginning Balance									$ 0.250	$ 0.035
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms									3 months 29 days	1 year
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Exercisable, Number	2,350,080								1,690,080	660,000
Share-based Compensation, Shares Authorized under Non Option Equity Instruments,, Exercise Price Range, Lower Range Limit									$ 0.01	$ 0.26
Share-based Compensation, Shares Authorized under Non Option Equity Instruments, Exercise Price Range, Upper Range Limit									$ 0.25	$ 0.99