Note 9 - Warranty

3 Months Ended

Jul. 31, 2013

Product Warranties Disclosures [Abstract]

Product Warranty Disclosure [Text Block]

9.           WARRANTY

The Company provides a limited warranty for a period of one year from the date of a customer’s receipt of its products, or one year from the installation date for some of its products, and will also provide an extended warranty for additional purchase price to the customer.  The Company’s standard warranties require the Company to repair or replace defective products at no cost to the customer or refund the customer’s purchase price.  The Company’s product warranty liability reflects management’s best estimate of probable liability under product warranties.  Management determines the liability based on known product failures (if any), historical experience, and other currently available evidence.

The following table presents changes in the Company’s warranty liability, which is included in accrued expenses on the balance sheets (in thousands):

	Three Months Ended July 31,
	2013			2012
Warranty reserve balance at beginning of period	$	90		$	163
Expense accrued, including adjustments		25			9
Warranty costs incurred		(21	)		(24	)
Warranty reserve balance at end of period	$	94		$	148