Consolidated Statements of Cash Flows (USD $)	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 1,669,860	$ 1,350,224
Adjustments to reconcile net income to net cash provided by operating activities:
Loss (gain) on sale of assets	4,363	(22,368)
Change in accounts receivable and inventory reserves	(25,570)	236,211
Depreciation and amortization	532,770	364,215
Change in cash surrender value of life insurance	(97,513)	(91,704)
Deferred income taxes	25,000	405,000
Warranty reserve	184,000	489,000
Compensation expense related to stock options	13,000	1,469
Change in operating assets and liabilities:
Accounts receivable	(2,692,701)	2,670,430
Notes receivable and other non-trade receivables	(48,002)	110,695
Inventories	4,590,984	(3,258,900)
Prepaid expenses and other assets	139,799	(365,636)
Accounts payable	(258,227)	(100,414)
Accrued expenses	(30,839)	(321,952)
Income taxes payable/ receivable	355,000	(714,000)
Total adjustments	2,692,064	(597,954)
Net cash provided by operating activities	4,361,924	752,270
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sale of investments		51,035
Proceeds from sale of assets	8,000	45,246
Capital expenditures	(375,045)	(1,001,786)
Net cash used in investing activities	(367,045)	(905,505)
CASH FLOWS FROM FINANCING ACTIVITIES:
Payment of cash dividend	(611,571)	(611,571)
Payment on capital leases		(8,271)
Proceeds from exercise of stock options		124,350
Tax effect from exercise and forfeiture of stock options		(52,156)
Net cash used in financing activities	(611,571)	(547,648)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	3,383,308	(700,883)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	5,814,184	6,515,067
CASH AND CASH EQUIVALENTS AT END OF YEAR	9,197,492	5,814,184
SUPPLEMENTAL SCHEDULE OF NON-CASH INVESTING ACTIVITIES:
Finished goods inventory transferred to equipment leased to customers	661,049
Cash paid during the year for:
Interest	22,000	1,800
Income taxes	$ 675,000	$ 1,088,000