Balance Sheets (USD $)	Sep. 30, 2012	Mar. 31, 2012
ASSETS
Cash and cash equivalents	$ 1,934,562	$ 1,544,536
Marketable securities, short term	15,907,264	17,551,629
Accounts receivable, net of allowance for uncollectible accounts of $15,000	1,961,682	2,684,840
Inventories	3,522,488	3,229,376
Prepaid expenses and other assets	1,287,755	1,159,852
Total current assets	24,613,751	26,170,233
Fixed assets
Machinery and equipment	8,211,475	7,488,211
Leasehold improvements	1,016,887	720,882
Gross fixed assets	9,228,362	8,209,093
Less accumulated depreciation	5,989,392	5,697,861
Net fixed assets	3,238,970	2,511,232
Marketable securities, long term	62,020,033	54,445,298
Total assets	89,872,754	83,126,763
LIABILITIES AND SHAREHOLDERS' EQUITY
Accounts payable	657,070	663,702
Accrued payroll and other	813,407	867,331
Deferred taxes	452,328	136,872
Total current liabilities	1,922,805	1,667,905
Shareholders' equity
Common stock, $0.01 par value, 6,000,000 shares authorized; 4,826,745 issued and outstanding as of September 30, 2012 and 4,824,745 issued and outstanding as of March 31, 2012	48,267	48,247
Additional paid-in capital	21,112,980	20,974,477
Accumulated other comprehensive income	1,619,483	1,087,456
Retained earnings	65,169,219	59,348,678
Total shareholders' equity	87,949,949	81,458,858
Total liabilities and shareholders' equity	$ 89,872,754	$ 83,126,763