Stock Warrant Liability (Tables)

3 Months Ended

Jun. 30, 2012

Stock Warrant Liability [Abstract]

Assumptions Used in Fair Value Calculations

The warrant had a term of 5 years and an exercise price of $4.25 per share. In the event of a change of control, the warrant must have been settled in cash using the Black-Scholes model in accordance with the underlying terms contained in the warrant agreement. The JH Transaction triggered the antidilution provisions contained in the warrant and, as a result, became exercisable for 8,018,868 shares of our common stock at an exercise price of $0.53 per share. The initial fair value of the warrant liability was determined by using the Black-Scholes valuation method as of August 30, 2006and this model has historically been used to determine fair value as of the end of each subsequent reporting period. The assumptions used included the closing price of our common stock on the valuation date, the strike price of the warrant, the risk-free rate equivalent to the U.S. Treasury maturities, the historical volatility of our common stock and the remaining term of the warrant. The assumptions used as of June 30, 2011 are as follows:

	June 30, 2011
Risk-free interest rate		0.02%
Expected term (in years)	0.17 years
Expected volatility		51.04%