Accounts Receivable

3 Months Ended

Oct. 31, 2012

Accounts Receivable Additional Disclosures [Abstract]

Accounts Receivable

(7)    Accounts Receivable

Accounts receivable consist of the following at:

	October 31, 2012		July 31, 2012
Billed receivables from commercial customers	$	35,209,000	41,139,000
Billed receivables from the U.S. government and its agencies	9,013,000		11,927,000
Unbilled receivables on contracts-in-progress	4,070,000		4,764,000
Total accounts receivable	48,292,000		57,830,000
Less allowance for doubtful accounts	1,365,000		1,588,000
Accounts receivable, net	$	46,927,000	56,242,000

Unbilled receivables on contracts-in-progress include $2,053,000 and $3,320,000 at October 31, 2012 and July 31, 2012, respectively, due from the U.S. government and its agencies. There was $13,000 of retainage included in unbilled receivables at both October 31, 2012 and July 31, 2012. In the opinion of management, a substantial portion of the unbilled balances will be billed and collected within one year.