Loss Per Share (Tables)

3 Months Ended

Mar. 31, 2014

Computation of Diluted Net Loss Per Share does not Assume Issuance of Common Shares that have an Anti-dilutive Effect on Net Loss Per Share

The computation of diluted net loss per share does not assume the issuance of common shares that have an anti-dilutive effect on net loss per share.

	Three Months Ended March 31,
	2014			2013
	(in thousands, except share and per share amounts)
Basic and diluted net loss per common share:
Net loss applicable to common stockholders	$	(5,408	)	$	(3,472	)
Weighted average common shares outstanding – basic and diluted		20,270			16,079
Net loss per common share – basic and diluted	$	(0.27	)	$	(0.22	)

Dilutive Shares Which Could Exist Pursuant to Exercise of Outstanding Stock Instruments and Which were not Included in Calculation

Dilutive shares which could exist pursuant to the exercise of outstanding stock instruments and which were not included in the calculation because their affect would have been anti-dilutive are as follows:

	March 31, 2014 (shares)		March 31, 2013 (shares)
Warrants to purchase shares of common stock		5,505,579		7,429,241
Options to purchase shares of common stock		3,365,198		3,656,217
Shares of common stock issuable upon conversion of preferred stock		2,550,437		2,618,772
		11,421,214		13,704,230