Note 13 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	Year Ended December 31,
	2019			2018
Statutory federal income tax benefit	$	(2,118,000	)	$	(9,591,000	)
Intangible assets		673,000			3,119,000
Change in valuation allowance		(681,000	)		(2,084,000	)
Expiration of net operating losses		1,187,000			1,271,000
United States tax reform rate change		--			--
Disallowed financing costs		1,119,000			240,000
State and local taxes		(205,000	)		2,344,000
Other		25,000			(29,000	)
Total income tax benefit	$	--		$	(4,730,000	)

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	Year Ended December 31,
	2019			2018
Deferred tax assets:
Net operating loss carryforwards	$	26,758,000		$	27,312,000
Income tax credit carryforwards		2,757,000			2,769,000
Stock compensation		384,000			850,000
Lease Obligation		185,000			--
Deferred Revenue		419,000			--
Other		943,000			1,027,000
Total deferred tax assets		31,446,000			31,958,000
Deferred tax liabilities
Indefinite lived intangible assets		--			--
Depreciation and amortization		(408,000	)		(419,000	)
Lease asset		(180,000	)		--
Total deferred tax liabilities		(588,000	)		(419,000	)
Valuation allowance		(30,858,000	)		(31,539,000	)
Net deferred taxes	$	--		$	--