11. Loss Per Share

Basic earnings (loss) per common share is determined by dividing earnings (loss) attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration of common stock equivalents. Diluted earnings (loss) per share are computed by dividing the earnings (loss) attributable to common stockholders by the weighted-average number of common share equivalents outstanding for the period. The treasury stock method is used to determine the dilutive effect of the Company’s stock option grants, potential Employee Stock Purchase Plan (ESPP) awards and warrants and the if-converted method is used to determine the dilutive effect of the Company’s Series A Preferred Stock. The following common stock equivalents were excluded in the calculation of diluted earnings (loss) per share because their effect would be anti-dilutive as applied to the loss from continuing operations as of March 31, 2013 and 2012:

	Three months ended March 31,
	2013	2012
Series A Preferred Stock	—	12,249,998
Warrants to purchase Series A Preferred Stock/Common Stock	15,276	143,749
Stock Options, Stock Appreciation Rights, Non-vested Stock Options, and ESPP Awards	190,418	528,163