CONDENSED STATEMENTS OF STOCKHOLDERS' DEFICIT - USD ($)	Total	Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]
Balance at Dec. 31, 2013	$ 5,253,222	$ 0	$ 122,449	$ 119,885,371	$ (114,754,598)
Balance (in shares) at Dec. 31, 2013		0	122,448,707
Net loss	(3,241,166)	$ 0	$ 0	0	(3,241,166)
Common stock issued:
Employee stock purchase plan	19,244	$ 0	$ 69	19,175	0
Employee stock purchase plan (in shares)		0	67,610
Stock-based compensation expense	244,799	$ 0	$ 0	244,799	0
Balance at Jun. 30, 2014	2,276,099	$ 0	$ 122,518	120,149,345	(117,995,764)
Balance (in shares) at Jun. 30, 2014		0	122,516,317
Balance at Dec. 31, 2013	5,253,222	$ 0	$ 122,449	119,885,371	(114,754,598)
Balance (in shares) at Dec. 31, 2013		0	122,448,707
Net loss	6,300,000
Balance at Dec. 31, 2014	4,516,857	$ 0	$ 172,686	125,434,483	(121,090,312)
Balance (in shares) at Dec. 31, 2014		0	172,683,342
Net loss	(4,009,981)	$ 0	$ 0	0	(4,009,981)
Common stock issued:
Private placement	(7,100)			(7,100)
Horizon Warrant	8,887			8,887
Employee stock purchase plan	10,844	$ 0	$ 103	10,741	0
Employee stock purchase plan (in shares)		0	103,565
Stock-based compensation expense	399,235	$ 0	$ 0	399,235	0
Balance at Jun. 30, 2015	$ 918,742	$ 0	$ 172,789	$ 125,846,246	$ (125,100,293)
Balance (in shares) at Jun. 30, 2015		0	172,786,907