Accounts Receivable (Tables)

9 Months Ended

Apr. 30, 2011

Accounts Receivable

Accounts receivable detail

	April 30, 2011	July 31, 2010
Billed receivables from the U.S. government and its agencies	$      23,349,000	89,843,000
Billed receivables from commercial customers	36,311,000	35,230,000
Unbilled receivables on contracts-in-progress	11,905,000	11,894,000
Total accounts receivable	71,565,000	136,967,000
Less allowance for doubtful accounts	1,380,000	1,127,000
Accounts receivable, net	$      70,185,000	135,840,000