Balance Sheets (USD $)	Sep. 30, 2013	Mar. 31, 2013
ASSETS
Cash and cash equivalents	$ 1,561,571	$ 2,509,683
Marketable securities, short term	8,330,034	9,711,029
Accounts receivable, net of allowance for uncollectible accounts of $15,000	3,031,027	2,521,395
Inventories	3,100,445	3,336,592
Deferred tax assets	256,472	0
Prepaid expenses and other assets	894,806	958,147
Total current assets	17,174,355	19,036,846
Fixed assets
Machinery and equipment	8,417,061	8,417,061
Leasehold improvements	1,499,454	1,499,454
Gross fixed assets	9,916,515	9,916,515
Less accumulated depreciation	6,608,394	6,228,122
Net fixed assets	3,308,121	3,688,393
Marketable securities, long term	79,140,911	73,040,257
Total assets	99,623,387	95,765,496
LIABILITIES AND SHAREHOLDERS' EQUITY
Accounts payable	391,640	422,092
Accrued payroll and other	894,282	918,060
Deferred taxes	0	440,736
Total current liabilities	1,285,922	1,780,888
Deferred Tax Liabilities, Net, Noncurrent	377,232	0
Shareholders' equity
Common stock, $0.01 par value, 6,000,000 shares authorized; 4,837,043 issued and outstanding as of September 30, 2013; 4,862,436 issued and outstanding as of March 31, 2013	48,370	48,624
Additional paid-in capital	19,990,791	21,200,742
Accumulated other comprehensive income	947,080	1,557,726
Retained earnings	76,973,992	71,177,516
Total shareholders' equity	97,960,233	93,984,608
Total liabilities and shareholders' equity	$ 99,623,387	$ 95,765,496