Annual report pursuant to section 13 and 15(d)

Weighted Average Assumptions to Value the Warrants (Detail)

v2.4.0.8
Weighted Average Assumptions to Value the Warrants (Detail) (USD $)
12 Months Ended
May 31, 2013
Debt Instrument [Line Items]  
Expected dividend yield 0.00%
Expected term 2 years
Risk-free interest rate 0.28%
Minimum
 
Debt Instrument [Line Items]  
Stock price volatility 70.00%
Grant-date fair value $ 0.11
Maximum
 
Debt Instrument [Line Items]  
Stock price volatility 94.00%
Grant-date fair value $ 1.10