10.	Loss per Share

Basic per share data is computed by dividing net income or loss applicable to common stockholders by the weighted average number of common shares outstanding during the period. Diluted per share data is computed by dividing net income or loss applicable to common stockholders by the weighted average number of common shares outstanding during the period increased to include, if dilutive, the number of additional common shares that would have been outstanding as calculated using the treasury stock method. Potential common shares were related entirely to outstanding but unexercised options and warrants for all periods presented.

We have excluded all potentially dilutive securities, including unvested performance-based restricted stock, from the calculation of diluted loss per share attributable to common stockholders for the three months ended March 31, 2013 and 2012, as their inclusion would be antidilutive. Potentially dilutive common shares excluded from the calculations of diluted loss per share were 19,536,812 for the three and six month periods ended June 30, 2013 and 18,401,231 for the three and six month periods ended June 30, 2012, respectively.