Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Jun. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 4,305,000	$ 7,363,000
Accounts receivable, net of allowance for doubtful accounts of $11 as of both June 30, 2023 and December 31, 2022	115,000	201,000
Prepaid expenses and other current assets	230,000	300,000
Total current assets	4,650,000	7,864,000
Property and equipment, net	139,000	170,000
Operating lease right-of-use asset, net	1,429,000	1,588,000
Other assets	171,000	171,000
Total assets	6,389,000	9,793,000
Current liabilities:
Accounts payable	686,000	683,000
Accrued expenses and other current liabilities	2,257,000	2,246,000
Deferred revenue	333,000	341,000
Operating lease liability - current	340,000	315,000
Total current liabilities	3,616,000	3,585,000
Operating lease liability - noncurrent	1,138,000	1,316,000
Total liabilities	4,754,000	4,901,000
Stockholders’ equity:
Preferred stock, $0.001 par value, 25,000,000 shares authorized and no shares issued and outstanding as of June 30, 2023 and December 31, 2022	0	0
Common stock, $0.001 par value, 100,000,000 shares authorized, 21,586,150 and 20,076,773 shares issued and outstanding as of June 30, 2023 and December 31, 2022, respectively	22,000	20,000
Additional paid-in capital	149,142,000	145,476,000
Accumulated deficit	(147,529,000)	(140,604,000)
Total stockholders’ equity	1,635,000	4,892,000
Total liabilities and stockholders’ equity	$ 6,389,000	$ 9,793,000