Inventories (Tables)

3 Months Ended

Jul. 31, 2012

Inventories [Abstract]

Schedule of Inventory, Current [Table Text Block]

	July 31, 2012		April 30, 2012
Raw materials	$	866,000	$	848,000
Work in process	332,000		296,000
Finished goods	101,000		85,000
	$	1,299,000	$	1,229,000