10. The method of claim 5 , including voiding the original transaction document using the processor.
5. A method of modifying a document comprising: providing a tangible computer storage medium; providing an original transaction document stored on the computer storage medium, wherein the original transaction document is an invoice; providing a general ledger stored on the computer storage medium, the general ledger including original transaction postings corresponding to transactions contained in the original transaction document; providing a processor configured to access the computer storage medium; opening the stored original transaction document using the processor, the original transactions of which are each selected from the group consisting of a product sale, a credit to an account and a debit to an account; modifying at least one of the original transactions in the original transaction document using the processor; saving the modified original transaction document as a new transaction document on the computer storage medium using the processor, wherein the new transaction document includes the non-modified original transactions and the at least one modified original transaction; nullifying the original transaction postings in the general ledger using the processor; and posting the non-modified original transactions and the at least one modified transaction of the new transaction document in the general ledger using the processor in response to saving the modified original transaction document.