Statements of Cash Flows - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating Activities
Net income	$ 95,800	$ 44,000
Adjustments to reconcile net income to net cash used in operating activities
Depreciation and amortization	1,800	1,700
Accretion of interest - convertible debentures		13,200
Cumulative effect of accounting change	96,100
Net income adjusted for non-cash operating activities	193,700	58,900
(Increase) decrease in assets
Accounts receivable	(90,500)	(40,100)
Inventory	2,000	9,800
Prepaid and other	(14,900)	(3,400)
Decrease in liabilities
Accounts payable and accrued expenses	(4,900)	(67,900)
Deferred revenue	(99,400)	(5,600)
Total increase in operating capital	(207,700)	(107,200)
Net cash used in operating activities	(14,000)	(48,300)
Investing Activities
Additions to fixed assets		(700)
Net cash used in investing activities		(700)
Financing Activities
Decrease in cash	(14,000)	(49,000)
Cash at beginning of year	360,400	199,100
Cash at end of period	$ 346,400	$ 150,100