Sorry for my vagueness before, I'll try to clear some things up..
The file that the guestbook writes to is more or less a flat-file database WITHOUT delimiters, so there isn't a way to single out entries unless a name, address, or zipcode-query is done to point to a certain area of the file to be edited.
Ultimately, I would like the script to be able to edit the flat-file html page thru an admin. page like the one submitted by "Tachyon" (see above)....just the ability to edit the contents of a flat-file database(without obvious delimiters) over the web.
Here is the guestbook script that creates the flat-file:
http://204.33.180.159:8080/guest.txt