CONSOLIDATED STATEMENT OF INCOME (unaudited) (USD $)	3 Months Ended				9 Months Ended
	Oct. 31, 2011		Oct. 31, 2010		Oct. 31, 2011		Oct. 31, 2010
CONSOLIDATED STATEMENT OF INCOME (unaudited) [Abstract]
Net sales	$ 25,245,131		$ 21,384,674		$ 71,764,377		$ 65,098,637
Cost of goods sold	15,910,283		13,589,638		46,234,343		41,478,910
Gross profit	9,334,848		7,795,036		25,530,034		23,619,727
Operating expenses
Selling	2,944,019		2,849,221		8,784,207		8,549,038
General and administrative	3,387,617		2,763,913		9,437,146		8,478,717
Total selling, general and administrative expenses	6,331,636		5,613,134		18,221,353		17,027,755
Income from operations	3,003,212		2,181,902		7,308,681		6,591,972
Interest expense	(47,153)		(50,201)		(145,862)		(159,887)
Other income, net	198,317		18,601		389,647		208,834
Income before taxes	3,154,376		2,150,302		7,552,466		6,640,919
Provision for taxes	1,072,490		731,103		2,567,839		2,257,912
Net income	$ 2,081,886		$ 1,419,199		$ 4,984,627		$ 4,383,007
Earnings per share, basic [1] (in dollars per share)	$ 0.14	[1]	$ 0.10	[1]	$ 0.34	[1]	$ 0.30	[1]
Earnings per share, diluted [2] (in dollars per share)	$ 0.14	[2]	$ 0.10	[2]	$ 0.34	[2]	$ 0.30	[2]
Cash dividend per share - declared [3] (in dollars per share)	$ 0.071	[3]	$ 0.066	[3]	$ 0.203	[3]	$ 0.186	[3]
Cash dividend per share - paid [3] (in dollars per share)	$ 0.066	[3]	$ 0.060	[3]	$ 0.198	[3]	$ 0.180	[3]

[1] Basic earnings per share are based upon the weighted average number of shares outstanding of 14,659,402 and 14,621,802 for the nine-month periods ended October 31, 2011 and 2010, respectively, and 14,659,383 and 14,620,439 for the three-month periods ended October 31, 2011 and 2010, respectively.

[2] Diluted earnings per share are based upon the weighted average number of shares outstanding of 14,788,493 and 14,717,084 for the nine-month periods ended October 31, 2011 and 2010, respectively, and 14,799,814 and 14,711,056 for the three-month periods ended October 31, 2011 and 2010, respectively.

[3] The Board of Directors declared a quarterly dividend of $.071 per share payable on December 16, 2011 to shareholders of record at the close of business on December 2, 2011. The Board of Directors declared quarterly dividends of $.066 per share payable on December 17, 2010, March 17, 2011, June 15, 2011 and September 15, 2011 to shareholders of record at the close of business on December 3, 2010, March 3, 2011, June 1, 2011 and September 1, 2011, respectively. The Board of Directors declared quarterly dividends of $.06 per share payable on March 12, 2010, June 11, 2010 and September 15, 2010 to shareholders of record at the close of business on February 26, 2010, May 28, 2010 and September 1, 2010, respectively.