CONDENSED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 5,840	$ 4,150
Investments	3,501	11,105
Accounts receivable, net	652	947
Prepaid expenses and other	1,099	226
Total current assets	11,092	16,428
Property and equipment, net	843	805
Other assets	253	197
Total assets	12,188	17,430
Current liabilities:
Accounts payable	1,129	1,500
Accrued expenses	1,418	2,183
Unearned revenue	1,424	4
Total current liabilities	3,971	3,687
Stockholders’ equity:
Preferred stock, $0.001 par value, 5,000 shares authorized; none issued and outstanding in 2013 and 2012	0	0
Common stock, $0.001 par value; 30,000 shares authorized; 12,948 shares issued and outstanding at June 30, 2013 and December 31, 2012	13	13
Additional paid-in capital	280,144	279,518
Accumulated other comprehensive loss	(8)	(27)
Accumulated deficit	(271,932)	(265,761)
Total stockholders' equity	8,217	13,743
Total liabilities and stockholders’ equity	$ 12,188	$ 17,430