STATEMENTS OF OPERATIONS - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Cost of sales	$ 2,500,407	$ 1,948,175
Gross profit	5,318,290	4,432,192
Operating expenses:
Selling, general and administrative	4,611,097	4,107,117
Income from operations	707,193	325,075
Loss on currency exchange	(9,675)	(10,912)
Interest income	70,447	102,888
Income before taxes	767,965	417,051
Income tax expense (benefit)	253,000	(166,000)
Net income	$ 514,965	$ 583,051
Net income per share - basic (in dollar per share)	$ 0.12	$ 0.13
Net income per share - diluted (in dollar per share)	$ 0.11	$ 0.13
Weighted-average shares outstanding - basic (in shares)	4,473,591	4,511,965
Weighted-average shares outstanding - diluted (in shares)	4,490,795	4,511,965