Accounts Receivable

3 Months Ended

Oct. 31, 2011

Accounts Receivable, Net [Abstract]

Accounts Receivable

(7)             Accounts Receivable

                Accounts receivable consists of the following:

	October 31, 2011	July 31, 2011
Billed receivables from commercial customers	$     44,055,000	38,245,000
Billed receivables from the U.S. government and its agencies	22,148,000	22,075,000
Unbilled receivables on contracts-in-progress	9,440,000	11,701,000
Total accounts receivable	75,643,000	72,021,000
Less allowance for doubtful accounts	1,171,000	1,220,000
Accounts receivable, net	$     74,472,000	70,801,000

Unbilled receivables on contracts-in-progress include $2,948,000 and $4,487,000 at October 31, 2011 and July 31, 2011, respectively, due from the U.S. government and its agencies. There was $28,000 of retainage included in unbilled receivables at both October 31, 2011 and July 31, 2011. In the opinion of management, substantially all of the unbilled balances will be billed and collected within one year.