STOCK-BASED COMPENSATION (Details 1) (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
NumberOutstanding	2,960,000	3,610,000	3,850,000	17,150,236	19,961,797	14,972,381	12,535,048	6,886,652
Weighted-Average Remaining Life In Years	1 year 11 months 8 days
Weighted- Average Exercise Price (in dollars per share)	$ 0.29	$ 0.55	$ 0.65	$ 0.3	$ 0.27	$ 0.51	$ 0.58	$ 0.64
Number Exercisable	2,960,000
Range One [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 0.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$ 0.25
NumberOutstanding	1,800,000
Weighted-Average Remaining Life In Years	2 years 4 months 2 days
Weighted- Average Exercise Price (in dollars per share)	$ 0.24
Number Exercisable	1,800,000
Range Two [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 0.26
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$ 1.00
NumberOutstanding	1,160,000
Weighted-Average Remaining Life In Years	1 year 3 months 25 days
Weighted- Average Exercise Price (in dollars per share)	$ 0.36
Number Exercisable	1,160,000