Lisa's Window Cleaning 3362 River Road Cambridge, Ohio Phone: (555) 782-9008 Fax: (555) 789-0939 E-mail: lisa@lisaswindows.com BILL TO: Claude Etheridge Spark Network Systems 89 Industrial Park Way Cambridge, Ohio Statement #: 1019976 Date: January 23rd 2007 Customer ID: V-941-A8 Date of Sale: November 5th 2006 Invoice #: 2903 Description: Bi-weekly window cleaning of high-rise building Amount: $1,500.00 (x 6 cleanings) Payment: $0.00 Balance: $4,500.00 Reminder: Please include the Statement Number on your check. Terms: Balance due in fourteen (14) days. What is the purpose of this invoice?