NOTE C - COSTS AND ESTIMATED EARNINGS IN EXCESS OF BILLINGS, NET (Details) - USD ($)	3 Months Ended		6 Months Ended
	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2016	Oct. 31, 2015
NOTE C - COSTS AND ESTIMATED EARNINGS IN EXCESS OF BILLINGS, NET (Details) [Line Items]
Revenues	$ 12,914,000	$ 16,003,000	$ 25,622,000	$ 32,684,000
Contracts Receivable, Claims and Uncertain Amounts, Expected to be Collected in Remainder of Fiscal Year	210,000		210,000
Contracts Accounted for under Percentage of Completion [Member]
NOTE C - COSTS AND ESTIMATED EARNINGS IN EXCESS OF BILLINGS, NET (Details) [Line Items]
Revenues	$ 5,100,000	$ 9,200,000	$ 12,400,000	$ 18,500,000