NOTE D - COSTS AND ESTIMATED EARNINGS IN EXCESS OF BILLINGS, NET (Details) - USD ($)	3 Months Ended
	Jul. 31, 2018	Jul. 31, 2017
NOTE D - COSTS AND ESTIMATED EARNINGS IN EXCESS OF BILLINGS, NET (Details) [Line Items]
Revenues	$ 11,011,000	$ 12,023,000
Contracts Receivable, Claims and Uncertain Amounts, Expected to be Collected in Remainder of Fiscal Year	70,000
Contracts Accounted for under Percentage of Completion [Member]
NOTE D - COSTS AND ESTIMATED EARNINGS IN EXCESS OF BILLINGS, NET (Details) [Line Items]
Revenues	$ 9,300,000	$ 6,400,000