Note 3 - Intangible Assets and Goodwill (Details) (USD $)
9 Months Ended
Jan. 31, 2014
Jan. 31, 2013
Apr. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]      
Amortization of Intangible Assets $ 154,000 $ 154,000  
Goodwill 1,942,000 1,942,000 1,942,000
Goodwill, Other Changes $ 0