6. Earnings (Loss) per common share (Details) - USD ($)	3 Months Ended		9 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share [Abstract]
Net income (loss)	$ 65,600	$ (36,900)	$ 62,200	$ (2,600)
Weighted average common shares outstanding	1,492,334	1,489,112	1,490,189	1,489,112
Dilutive securities	38	0	1,309	0
Weighted average dilutive common shares outstanding	1,492,372	1,489,112	1,491,498	1,489,112
Basic earnings (loss) per common share	$ .04	$ (.02)	$ .04	$ 0.00
Diluted earnings (loss) per common share	$ 0.04	$ (0.02)	$ 0.04	$ 0.00