Balance Sheets (USD $)	May 31, 2012	May 31, 2011
Current assets:
Cash and cash equivalents	$ 73,952	$ 2,193,534
Accounts receivable, net (Note 2)	5,610,328	2,136,848
Inventory (Note 3)	8,372,535	5,352,424
Prepaid expenses	482,317	539,900
Prepaid income taxes		239,030
Costs and estimated earnings in excess of billings (Note 4)	5,492,028	4,189,799
Deferred income taxes (Note 10)	950,400	818,900
Total current assets	20,981,560	15,470,435
Maintenance and other inventory, net (Note 5)	844,834	846,177
Property and equipment, net (Note 6)	4,481,953	3,413,446
Cash value of life insurance, net	153,550	147,970
Total assets	26,461,897	19,878,028
Current liabilities:
Short-term borrowings (Note 7)	258,000
Current portion of long-term debt (Note 8)	3,657	5,485
Accounts payable	3,361,742	1,292,095
Accrued commissions	631,221	433,355
Other accrued expenses	2,116,755	1,329,341
Billings in excess of costs and estimated earnings (Note 4)	668,900	152,505
Accrued income taxes	140,977
Total current liabilities	7,181,252	3,212,781
Long-term debt (Note 8)		3,657
Deferred income taxes (Note 10)	283,985	278,485
Stockholders' Equity:
Common stock, $.025 par value, authorized 8,000,000 shares, issued 3,839,819 and 3,732,842 shares	95,995	93,321
Paid-in capital	7,276,694	6,627,463
Retained earnings	14,122,954	11,924,023
Treasury stock - 530,143 and 501,643 shares at cost	(2,498,983)	(2,261,702)
Total stockholders' equity	18,996,660	16,383,105
Total liabilities and stockholders' equity	$ 26,461,897	$ 19,878,028