Condensed Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating activities:
Net income (loss)	$ (2,125,857)	$ 752,142
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	252,471	274,339
Amortization of right-of-use assets	268,155	0
Stock based compensation	432,044	226,160
Provision for (recovery of) accounts receivable allowances	8,549	5,651
Provision for inventory reserves	19,983	(120,420)
Changes in operating assets and liabilities:
Accounts receivable	(1,996,450)	(2,176,171)
Inventories	1,565,903	(978,071)
Prepaid expenses and other assets	533,486	(102,005)
Operating lease liabilities	(293,489)	0
Accounts payable and accrued expenses	494,221	123,722
Net cash provided by (used in) operating activities	(839,984)	(1,994,653)
Investing activities:
Cost of other assets	(135,000)	(23,560)
Purchases of plant and equipment	(120,715)	(207,181)
Net cash provided by (used in) investing activities	(255,715)	(230,741)
Financing activities:
Net proceeds from (payments to) bank credit lines	(1,741,272)	1,859,590
Net proceeds from private placement offering	4,942,609	0
Proceeds from stock option exercises	48,200	374,758
Net cash provided by (used in) financing activities	3,249,537	2,234,348
Net change in cash	2,153,838	8,954
Cash and cash equivalents at beginning of period	125,982	229,218
Cash and cash equivalents at end of period	2,279,820	238,172
Supplemental disclosures of cash flow information:
Cash paid during the period for: Interest	48,405	44,763
Cash paid during the period for: Income taxes	$ 24,319	$ 21,493