Allday Consulting's Peachtree and QuickBooks Support Boards

I have not been using quickbook since in college. I am trying to help out my colleage about quickbook. He having questions about the accounts receivable. Here are the following thing he did on the quick book, he only recorded when the payment received, but he never send out the invoice to collect the money in accounts receivable. In the balance sheet, they show the balance he actual got in the bank, but the accounts receivable show negative balance that he think the system error record amount the customer owe. In reality, there are no money owe to us. Any suggestion how we can track it in accounts receivable...why are they show negative balance in accounts receivable in the balance sheet? Any advise would be appreciated.

Thanks!