Balance Sheets (USD $)	Jun. 30, 2012	Mar. 31, 2012
ASSETS
Cash and cash equivalents	$ 1,493,518	$ 1,544,536
Marketable securities, short term	18,903,884	17,551,629
Accounts receivable, net of allowance for uncollectible accounts of $15,000	2,947,096	2,684,840
Inventories	3,547,096	3,229,376
Deferred tax assets	0	0
Prepaid expenses and other assets	1,199,691	1,159,852
Total current assets	28,091,285	26,170,233
Fixed assets
Machinery and equipment	7,876,694	7,488,211
Leasehold improvements	777,585	720,882
Gross fixed assets	8,654,279	8,209,093
Less accumulated depreciation	5,837,132	5,697,861
Net fixed assets	2,817,147	2,511,232
Marketable securities, long term	56,664,385	54,445,298
Total assets	87,572,817	83,126,763
LIABILITIES AND SHAREHOLDERS' EQUITY
Accounts payable	603,056	663,702
Accrued payroll and other	730,440	867,331
Income taxes payable	1,397,138	0
Deferred taxes	91,295	136,872
Total current liabilities	2,821,929	1,667,905
Shareholders' equity
Common stock, $0.01 par value, 6,000,000 shares authorized; 4,824,745 issued and outstanding as of June 30 and March 31, 2012	48,247	48,247
Additional paid-in capital	20,974,477	20,974,477
Accumulated other comprehensive income	1,001,828	1,087,456
Retained earnings	62,726,336	59,348,678
Total shareholders' equity	84,750,888	81,458,858
Total liabilities and shareholders' equity	$ 87,572,817	$ 83,126,763