CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Operating activities:
Net income (loss)	$ (74,277)	$ (1,366,999)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Stock based compensation	399,779	196,313
Depreciation and amortization	365,076	500,078
Provision (recovery) for accounts receivable allowances	(1,080)	(677)
Provision (recovery) for inventory reserves	(77,698)	200,357
Changes in operating assets and liabilities:
Accounts receivable	(530,014)	269,424
Inventories	(2,647,677)	(476,048)
Prepaid expense and other current assets	(305,739)	35,116
Accounts payable and accrued expenses	1,068,035	1,976,896
Net cash provided by (used in) operating activities	(1,803,595)	1,334,460
Investing activities:
Purchases of plant and equipment	(236,910)	(99,790)
Cost of other assets	(93,000)	(150,000)
Net cash provided by (used in) investing activities	(329,910)	(249,790)
Financing activities:
Proceeds from stock option exercise	379,257	181,062
Net (payments to) proceeds from bank credit lines	1,651,012	(1,216,360)
Net cash provided by (used in) financing activities	2,030,269	(1,035,298)
Net change in cash	(103,236)	49,372
Cash and cash equivalents at beginning of year	229,218	179,846
Cash and cash equivalents at end of year	125,982	229,218
Cash paid during the period for:
Interest	78,396	98,757
Income taxes	$ 25,798	$ 14,660