Note 5 - Stockholders' Equity (Detail) - Equity award activity (USD $)	9 Months Ended		12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Apr. 30, 2012
Number of Shares - Stock Options Outstanding	235,750		234,250
Weighted-Average Exercise Price - Stock Options Oustanding (in Dollars per share)	$ 4.28		$ 3.78
Weighted-Average Remaining Contract Life - Stock Options Oustanding	6 years 200 days		5 years 116 days
Outstanding exercisable at January 31, 2013	138,583
Outstanding exercisable at January 31, 2013 (in Dollars per share)	$ 4.26
Outstanding exercisable at January 31, 2013	4 years 332 days
Number of Shares - Restricted Stock	11,007		7,200
Weighted-Average Exercise Price - Restricted Stock (in Dollars per share)	$ 4.64		$ 5.01
Weighted-Average Remaining Contract Life - Restricted Stock	9 years 51 days		9 years
Granted	49,000
Granted (in Dollars per share)	$ 3.74
Granted	9 years 6 months
Exercised	47,500
Exercised (in Dollars per share)	$ 1.25
Granted	6,207
Granted (in Dollars per share)	$ 4.35	$ 4.35
Granted	9 years 3 months
Issued	2,400
Issued (in Dollars per share)	$ 5.01