10.

Loss Per Share

Basic loss per share is based on the weighted-average number of common shares outstanding during each period. Diluted loss per share is based on basic shares as determined above plus the incremental shares that would be issued upon the assumed exercise of in-the-money stock options and warrants using the treasury stock method. 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. For the years ended December 31, 2011 and 2010, all stock options, warrants and potential shares related to conversion of the Series A, the Series B and the Series C were excluded from the computation of diluted net loss per share. 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:


	December 31,
	2011		2010
	(Shares)		(Shares)
Warrants to purchase shares of common stock		6,673,405		8,585,872
Options to purchase shares of common stock		3,091,474		1,965,709
Restricted shares subject to vesting		—		26,042
Shares of common stock issuable upon conversion preferred stock		2,627,110		2,633,110

		12,391,989		13,210,733