1. ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 2) - Stock Option - USD ($)	12 Months Ended
	May. 31, 2015	May. 31, 2014	May. 31, 2013
Fair Value Assumptions for Stock Options Granted
Expected term (in years)	4 years	4 years	5 years
Volatility	90.00%	95.00%	91.00%
Expected dividend	$ 0	$ 0	$ 0
Risk-free Interest Rates	1.20%	1.39%	0.72%
Weighted Average Grant Date Fair Value	$ 1.52	$ 1.09	$ 0.78