CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jul. 31, 2012	Jul. 31, 2011
Cash flows from operating activities:
Net income (loss)	$ 916	$ (752)
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities:
Depreciation and amortization	41	32
Warranty reserve expense	65	2
Changes in operating assets and liabilities:
Accounts receivable	(168)	128
Costs and estimated earnings in excess of billings on uncompleted contracts	(957)	32
Deferred cost of revenue	3	38
Inventories	550	(471)
Other current assets	111	(101)
Accounts payable	(799)	401
Billings in excess of costs and estimated earnings on uncompleted contracts	0	(85)
Accrued payroll and related taxes	54	55
Warranty reserves	(60)	(9)
Other liabilities	(30)	(13)
Deferred revenues	(11)	862
Net cash (used in) provided by operating activities	(285)	119
Cash flows from investing activities:
Purchases of certificates of deposit	0	(250)
Proceeds from redemption of certificates of deposit	250	499
Additions to equipment, furniture and fixtures	(64)	(24)
Net cash provided by investing activities	186	225
Net (decrease) increase in cash and cash equivalents	(99)	344
Cash and cash equivalents at beginning of period	2,783	3,881
Cash and cash equivalents at end of period	2,684	4,225
Supplemental cash flow information:
Cash paid for income taxes	$ 25	$ 0