Net Loss Per Share

6 Months Ended

Jun. 30, 2013

Net Loss Per Share

Net Loss Per Share

(3)  Net Loss Per Share

Basic net loss per common share is based upon the weighted-average number of common shares outstanding during the period, excluding restricted stock that has been issued but is not yet vested. Diluted net loss per common share is based upon the weighted-average number of common shares outstanding during the period plus additional weighted-average potentially dilutive common shares outstanding during the period when the effect is dilutive. The potentially dilutive common shares that have not been included in the net loss per common share calculations because the effect would have been anti-dilutive are as follows:

	Six months ended June 30,
	2013	2012
Stock options	5,005,603	4,304,897
Restricted stock	12,000	12,000
	5,017,603	4,316,897