XML 99 R33.htm IDEA: XBRL DOCUMENT

Assumptions used to Calculate Fair Value of Options on Date of Grant (Detail)	3 Months Ended
	May 31, 2013	May 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-Free Interest Rate:	0.60%	0.70%
Expected Dividend Yield:	0.00%	0.00%
Expected Life (Years):	4 years 3 months 18 days	4 years 2 months 12 days
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected Volatility:		129.50%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected Volatility:	115.90%	131.40%

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References+ Details