Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash	$ 7,582	$ 9,097
Accounts receivable	812	2,123
Prepaid expenses and other current assets	731	550
Total current assets	9,125	11,770
Deposit	68	68
Property and equipment, net	328	330
Total assets	9,521	12,168
Current liabilities:
Accounts payable	321	539
Accrued expenses	984	804
Deferred revenue	2,920	2,725
Total current liabilities	4,225	4,068
Total liabilities	4,225	4,068
Stockholders' equity:
Common stock, 70,000,000 shares authorized with par value $0.001per share; 33,875,625 and 33,331,182 shares issued and outstanding at March 31, 2013 and December 31, 2012, respectively	34	33
Additional paid - in capital	147,429	146,677
Accumulated other comprehensive income	18	5
Accumulated deficit	(142,185)	(138,615)
Total stockholders' equity	5,296	8,100
Total liabilities and stockholders' equity	9,521	12,168
Series A Preferred Stock
Stockholders' equity:
Preferred stock, value
Series B Preferred Stock
Stockholders' equity:
Preferred stock, value