You could always keep two records (and maybe you should) - one online, backed up somewhere, where you can record the information and edit it, and another bound (literally) and in ink where you just copy what you did in the electronic format.
By the way, generally speaking, remember that if you EVER need to make changes to a bound record that is required by the government and subject to inspection by a government agent or court, the proper procedure is to single-line out the error, make the correction, and then initial and date the whole affair. Depending on how obvious the error is, you may also do well to write a note explaining the change, lest you forget the details five yeas later when your books are inspected.