Condensed Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Operating activities:
Net income (loss)	$ 752,142	$ (980,387)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	274,339	391,181
Stock based compensation	226,160	170,074
Provision for accounts receivable allowances	5,651	540
Provision for (recovery of) inventory reserves	(120,420)	186,440
Changes in operating assets and liabilities:
Accounts receivable	(2,176,171)	393,164
Inventories	(978,071)	(566,490)
Prepaid expenses and other assets	(102,005)	(327,462)
Accounts payable and accrued expenses	123,722	1,421,963
Net cash provided by (used in) operating activities	(1,994,653)	689,023
Investing activities:
Cost of other assets	(23,560)	(75,000)
Purchases of plant and equipment	(207,181)	(93,849)
Net cash provided by (used in) investing activities	(230,741)	(168,849)
Financing activities:
Net funds received from (paid to) bank credit lines	1,859,590	(711,842)
Proceeds from stock option exercises	374,758	102,675
Net cash provided by (used in) financing activities	2,234,348	(609,167)
Net change in cash	8,954	(88,993)
Cash and cash equivalents at beginning of period	229,218	179,846
Cash and cash equivalents at end of period	238,172	90,853
Supplemental disclosures of cash flow information:
Cash paid during the period for: Interest	44,763	87,178
Cash paid during the period for: Income taxes	$ 21,493	$ 14,123