Earnings Per Share (Tables)

6 Months Ended

Jun. 30, 2012

Earnings Per Share [Abstract]

Schedule of the components of the calculations of basic and diluted earnings per share

		Three Months Ended					Six Months Ended
		June 30, 2012			June 30, 2011		June 30, 2012		June 30, 2011
Numerator:
	Net loss		$	(6,479,554)	$	(6,752,668)	$	(13,062,656)	$	(13,995,868)
Denominator:
	Weighted average number of common shares outstanding		37,853,358		16,320,235		30,645,479		14,781,215

Schedule of potential dilutive common shares

	At June 30,
	2012		2011
Stock options outstanding		2,005,657	1,059,953
Unvested restricted stock		275,262	409,164
Common stock warrants  (1)		9,421,008	7,128,563
Number of dilutive potential common shares		11,701,927	8,597,680

⁽¹⁾ On May 31, 2011, the Company granted 7,128,563 warrants as part of an underwritten public offering.  As a result of the March 28 and 29, 2012 public offerings described in Note 5, the number of warrants increased to 9,421,008.