Inventories (Tables)

12 Months Ended

Apr. 30, 2012

Inventories [Abstract]

Schedule of Inventory, Current [Table Text Block]

	2012		2011
Raw materials	$	848,000	$	983,000
Work in process	296,000		300,000
Finished goods	85,000		118,000
	$	1,229,000	$	1,401,000