4.	Net income (loss) per common share:

Basic net income (loss) per common share is computed by dividing the net income (loss) by the weighted average number of common shares outstanding for the period. Diluted net income (loss) per common share is computed by adjusting the numerator and denominator of the basic net income (loss) per share calculation for the potential impact of dilutive securities.

For the three and six month periods ended June 30, 2017, 2,228,637 and 2,086,072 stock options, respectively, were excluded from the calculation of diluted net income per common share as their inclusion would be anti-dilutive (three and six months ended June 30, 2016 – 1,934,452 and 1,841,096, respectively).

The following is a reconciliation of the numerators and denominators of basic and diluted net loss per common share:

	Three Months Ended June 30,						Six Months Ended June 30,
	2017			2016			2017			2016
Numerator:
Net loss used to compute net loss per common share:
Basic	$	(7,380	)	$	(6,016	)	$	(14,897	)	$	(9,279	)
Adjustment for change in fair value of liability classified stock options		(30	)		(58	)		(162	)		(100	)
Diluted	$	(7,410	)	$	(6,074	)	$	(15,059	)	$	(9,379	)
Denominator:
Weighted average number of common shares:
Basic		17,997,194			14,408,108			17,971,702			14,401,054
Adjustment for dilutive effect of stock options		18,554			26,494			23,407			27,106
Diluted		18,015,748			14,434,602			17,995,109			14,428,160
Net loss per common share - basic	$	(0.41	)	$	(0.42	)	$	(0.83	)	$	(0.64	)
Net loss per common share - diluted	$	(0.41	)	$	(0.42	)	$	(0.84	)	$	(0.65	)