Note 4 - Inventory (Details) - Inventories (USD $)
In Thousands, unless otherwise specified
Jan. 31, 2014
Apr. 30, 2013
Inventories [Abstract]    
Raw material $ 3,838 $ 3,077
Work-in-process 1,612 1,409
Finished goods 2,992 2,434
8,442 6,920
Reserves (602) (682)
$ 7,840 $ 6,238