NOTE C - COSTS AND ESTIMATED EARNINGS IN EXCESS OF BILLINGS, NET (Details) - Costs and Estimated Earnings in Excess of Billings, Net (USD $) In Thousands, unless otherwise specified	Jul. 31, 2013	Apr. 30, 2013
Costs and Estimated Earnings in Excess of Billings, Net [Abstract]
Costs and estimated earnings in excess of billings	$ 10,343	$ 10,228
Billings in excess of costs and estimated earnings	(4,080)	(1,611)
Net asset	$ 6,263	$ 8,617