v2.4.0.8
4. Stockholders' Equity (Details)
6 Months Ended
Jun. 30, 2013
Jun. 30, 2012
Stockholders Equity Details    
Expected Term 5 years 5 years
Volatility, minimum 118.00% 98.00%
Volatility, maximum 131.00% 115.00%
Dividend yield 0.00% 0.00%
Risk-free interest rate, minimum 0.81% 0.27%
Risk-free interest rate, maximum 2.52% 2.11%