Condensed Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2012	Jan. 31, 2011
Condensed Consolidated Statements of Income [Abstract]
Net sales	$ 15,080	$ 13,278	$ 28,585	$ 25,354
Cost of sales	6,108	5,548	11,696	10,605
Gross profit	8,972	7,730	16,889	14,749
Operating expenses
Research and development	923	986	1,713	1,705
Sales and marketing	2,906	2,734	5,983	5,757
General and administrative	2,525	2,176	5,063	4,427
Total operating expenses	6,354	5,896	12,759	11,889
Operating income	2,618	1,834	4,130	2,860
Other income (expenses)
Investment income	9	28	23	60
Interest expense	(15)	(65)	(33)	(145)
Loss on sale of product line	0	(99)	0	(99)
Miscellaneous	(4)	(4)	(6)	(11)
Total other income (expenses)	(10)	(140)	(16)	(195)
Income from continuing operations before provision for income taxes	2,608	1,694	4,114	2,665
Provision for income taxes	741	378	1,094	719
Income from continuing operations	1,867	1,316	3,020	1,946
Loss from discontinued operations, net of income tax benefit of $193 and $2, respectively	0	(4)	382	(7)
Net income	$ 1,867	$ 1,320	$ 2,638	$ 1,953
Basic
Income from Continuing Operations (in dollars per share)	$ 0.07	$ 0.05	$ 0.12	$ 0.08
Loss from Discontinued Operations (in dollars per share)	$ 0.00	$ 0.00	$ (0.02)	$ 0.00
Net Income (in dollars per share)	$ 0.07	$ 0.05	$ 0.10	$ 0.08
Diluted
Income from Continuing Operations (in dollars per share)	$ 0.07	$ 0.05	$ 0.12	$ 0.08
Loss from Discontinued Operations (in dollars per share)	$ 0.00	$ 0.00	$ (0.02)	$ 0.00
Net Income (in dollars per share)	$ 0.07	$ 0.05	$ 0.10	$ 0.08
Basic weighted average common shares outstanding (in share)	25,085,296	24,937,463	25,028,165	24,860,188
Diluted weighted average common shares outstanding (in share)	25,280,449	25,074,230	25,200,831	24,977,399