Condensed Consolidated Balance Sheets (USD $)	Feb. 29, 2012	May 31, 2011
Current assets:
Cash and cash equivalents		$ 2,193,534
Accounts receivable, net		2,136,848
Inventory		5,352,424
Costs and estimated earnings in excess of billings		4,189,799
Other current assets		1,597,830
Total current assets		15,470,435
Maintenance and other inventory, net		846,177
Property and equipment, net		3,413,446
Other assets		147,970
Total assets		19,878,028
Current liabilities:
Current portion of long-term debt		5,485
Accounts payable		1,292,095
Accrued commissions		433,355
Billings in excess of costs and estimated earnings		152,505
Other current liabilities		1,329,341
Total current liabilities		3,212,781
Long-term liabilities		282,142
Stockholders' Equity:
Common stock and additional paid-in capital		6,720,784
Retained earnings		11,924,023
Treasury stock - at cost		(2,261,702)
Total stockholders'equity		16,383,105
Total liabilities and stockholders' equity		19,878,028
Unaudited
Current assets:
Cash and cash equivalents	641,429	2,193,534
Accounts receivable, net	3,447,810
Inventory	8,029,278
Costs and estimated earnings in excess of billings	5,490,490
Other current assets	1,438,236
Total current assets	19,047,243
Maintenance and other inventory, net	808,668
Property and equipment, net	3,970,160
Other assets	152,201
Total assets	23,978,272
Current liabilities:
Current portion of long-term debt	5,028
Accounts payable	2,570,960
Accrued commissions	691,892
Billings in excess of costs and estimated earnings	788,905
Other current liabilities	1,716,425
Total current liabilities	5,773,210
Long-term liabilities	278,485
Stockholders' Equity:
Common stock and additional paid-in capital	7,079,741
Retained earnings	13,260,094
Treasury stock - at cost	(2,413,258)
Total stockholders'equity	17,926,577
Total liabilities and stockholders' equity	$ 23,978,272