Condensed Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Jul. 31, 2017	Jul. 31, 2016
Cash Flows from Operating Activities:
Net Income	$ 518,000	$ 567,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	41,000	44,000
(Gain) loss on sale of investments	38,000	(60,000)
Impairment of investments		13,000
Reserve for bad debts		1,000
Reserve for obsolete inventory		20,000
Deferred income taxes	7,000	(21,000)
(Gain) loss on sale of assets	(4,000)
(Increase) decrease in:
Accounts receivable	257,000	125,000
Inventories	(62,000)	136,000
Prepaid expenses	63,000	(28,000)
Employee receivables	1,000	(1,000)
Income tax overpayment	208,000
Increase (decrease) in:
Accounts payable	112,000	47,000
Accrued expenses	(163,000)	(105,000)
Income tax payable		255,000
Net cash provided by (used in) operating activities	1,016,000	993,000
Cash Flows From Investing Activities:
Proceeds from sale of assets	4,000
(Purchase) of property and equipment	(253,000)	(25,000)
Proceeds from sale of marketable securities	2,000	4,000
(Purchase) of marketable securities	(224,000)	(257,000)
Net cash provided by (used in) investing activities	(471,000)	(278,000)
Cash Flows From Financing Activities:
(Purchase) of treasury stock	(3,000)	(1,000)
Net cash provided by (used in) financing activities	(3,000)	(1,000)
Net Increase (Decrease) in Cash and Cash Equivalents	542,000	714,000
Cash and Cash Equivalents, beginning of period	6,456,000	5,918,000
Cash and Cash Equivalents, end of period	6,998,000	6,632,000
Supplemental Disclosure for Cash Flow Information:
Income taxes paid	0	0
Interest paid	$ 0	$ 0