Stockholders' Equity

6 Months Ended

Jun. 30, 2013

Stockholders' Equity Note [Abstract]

Stockholders' Equity

(5) Stockholders’ Equity

The table below sets forth the outstanding warrants to purchase shares of common stock as of June 30, 2013:

Offering Date	Outstanding Warrants		Exercise Price		Expiration Date	Status
May 2009		711,539	$	8.58	5/29/2014		Exercisable
February 2010		420,000	$	27.50	2/1/2015		Exercisable
		1,131,539

On June 11, 2013, 220,383 warrants with an exercise price of $20.16 issued in June 2008 expired. There were no warrants exercised during the six months ended June 30, 2013.