Inventories (Tables)

9 Months Ended

Jan. 31, 2013

Inventories [Abstract]

Schedule of Inventory, Current [Table Text Block]

	January 31, 2013		April 30, 2012
Raw materials	$	971,000	$	848,000
Work in process	291,000		296,000
Finished goods	261,000		85,000
	$	1,523,000	$	1,229,000