10. Stockholders' equity (Details Narrative) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Aggregate intrinsic value for options	$ 286,000	$ 242,300
Stock-based compensation expense	0	0
Redemption of shares, Shares	15,000,000
Redemption of shares, Amount	6,000,000	0
Issued price per share	$ 0.15	$ 0.19	$ 0.23
Stock option exercised	(55,000)	0
Stock option exercised amount	(9,350)	0
Stock option exercised price per share	$ 0.17
Stock Option outstanding	520,000
Stock Option Plan 1999 [Member]
Stock Option outstanding	0	0
Options expired unexercised	0	0
Stock Option Plan 2001 [Member]
Stock option exercised	1,989,700	1,934,700
Stock Option outstanding	0	605,000
Options expired unexercised	550,000	585,000
Stock Option Issued	1,989,700	2,539,700
Stock Option Plan 2005 [Member]
Stock option exercised price per share	$ 0.15
Stock Option outstanding	520,000	805,000
Options expired unexercised	285,000	150,000
Common Stock
Private placement of shares	1,750,000	2,000,000
Price Per share	$ 0.40	$ 0.45
Proceeds of common stock	700,000	900,000
Redemption of shares, Shares	15,000,000
Redemption of shares, Amount	2,250,000
Issued price per share	$ 0.15
Stock option exercised	55,000
Stock option exercised amount	(9,350)
Stock option exercised price per share	$ 0.17
Common Stock | Private Placement [Member]
Private placement of shares	1,000,000
Price Per share	$ 0.70
Proceeds of common stock	700,000
Accumulated Deficit
Redemption of shares, Amount	$ 3,750,000