Balance Sheets (USD $)	Dec. 31, 2012	Mar. 31, 2012
ASSETS
Cash and cash equivalents	$ 843,023	$ 1,544,536
Marketable securities, short term	15,610,697	17,551,629
Accounts receivable, net of allowance for uncollectible accounts of $15,000	2,621,780	2,684,840
Inventories	3,755,523	3,229,376
Prepaid expenses and other assets	1,333,019	1,159,852
Total current assets	24,164,042	26,170,233
Fixed assets
Machinery and equipment	8,343,525	7,488,211
Leasehold improvements	1,416,971	720,882
Gross fixed assets	9,760,496	8,209,093
Less accumulated depreciation	6,100,071	5,697,861
Net fixed assets	3,660,425	2,511,232
Marketable securities, long term	64,774,808	54,445,298
Total assets	92,599,275	83,126,763
LIABILITIES AND SHAREHOLDERS' EQUITY
Accounts payable	558,935	663,702
Accrued payroll and other	760,955	867,331
Deferred taxes	452,560	136,872
Total current liabilities	1,772,450	1,667,905
Shareholders' equity
Common stock, $0.01 par value, 6,000,000 shares authorized; 4,860,436 issued and outstanding as of December 31, 2012 and 4,824,745 issued and outstanding as of March 31, 2012	48,604	48,247
Additional paid-in capital	21,112,651	20,974,477
Accumulated other comprehensive income	1,597,009	1,087,456
Retained earnings	68,068,561	59,348,678
Total shareholders' equity	90,826,825	81,458,858
Total liabilities and shareholders' equity	$ 92,599,275	$ 83,126,763