Balance Sheets - USD ($)	Jun. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 3,629,273	$ 7,270,301
Accounts receivable, net of allowance of $119,620 and $131,464 in 2015 and 2014, respectively	7,449,913	6,480,499
Inventories	5,498,917	6,371,903
Prepaid expenses and other current assets	739,292	1,094,837
Total current assets	17,317,395	21,217,540
Property and equipment, net	1,077,011	894,728
Intangible assets, net	1,229,736	1,379,653
Other assets	321,309	388,850
Total assets	19,945,451	23,880,771
Current liabilities:
Accounts payable	2,293,119	2,353,133
Accrued liabilities	6,002,767	5,505,142
Deferred revenue	6,342,452	6,658,170
Warrants	2,027,395	2,134,187
Total current liabilities	16,665,733	16,650,632
Long-term debt, less current maturities	18,308,436	18,388,764
Long-term deferred revenue	856,854	976,165
Other liabilities	$ 5,570	$ 414,928
Stockholders' deficit:
Preferred stock, par value $0.001; 10,000,000 shares authorized, none outstanding at 2015 and 2014
Common stock, par value $0.001; 300,000,000 shares authorized, 21,066,848 and 20,480,874 shares issued at 2015 and 2014, respectively	$ 21,067	$ 20,481
Additional paid in capital	447,573,961	446,241,703
Treasury stock, 4,015 shares at 2015 and 2014	(205,999)	(205,999)
Accumulated deficit	(463,280,171)	(458,605,903)
Total stockholders' deficit	(15,891,142)	(12,549,718)
Total liabilities and stockholders' deficit	$ 19,945,451	$ 23,880,771