CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
Apr. 30, 2012	Apr. 30, 2011
Cash flows from operating activities:
Net income (loss)	$ 1,233	$ (951)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	141	119
Inventory obsolescence reserve	334	340
Warranty reserve expense	159	37
Impairment charge for patent write-off	16	12
Changes in operating assets and liabilities:
Accounts receivable	(586)	297
Costs and estimated earnings in excess of billings on uncompleted contracts	(694)	772
Deferred cost of revenue	107	(113)
Inventories	(2,557)	266
Other current assets	(106)	92
Accounts payable	918	(470)
Billings in excess of costs and estimated earnings on uncompleted contracts	(231)	(209)
Accrued payroll and related taxes	62	(23)
Warranty reserves	(21)	(48)
Payable to Parent	1	1
Other liabilities	(4)	29
Deferred revenues	72	271
Net cash provided by (used in) operating activities	(1,156)	422
Cash flows from investing activities:
Purchases of certificates of deposit	(500)	(997)
Proceeds from redemption of certificates of deposit	749	2,243
Additions to equipment, furniture and fixtures	(191)	(157)
Additions to intangible assets	0	(7)
Proceeds from sale of equipment	0	14
Net cash provided by investing activities	58	1,096
Net increase (decrease) in cash and cash equivalents	(1,098)	1,518
Cash and cash equivalents at beginning of period	3,881	2,363
Cash and cash equivalents at end of period	$ 2,783	$ 3,881

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Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits are not generally reported as cash and cash equivalents. Includes cash and cash equivalents associated with the entity's continuing operations. Excludes cash and cash equivalents associated with the disposal group (and discontinued operation).