check for duplicate databases

I have a program that I am writing in PHP/MySQL. I have made some upgrades
to the database and like an idiot, forgot to write down the changes or to
make the changes in several other databases for the other clients that are
using the program also. What I am trying to do is to have a program,
(preferably in PHP) that will look at the structure of the main database
that I changed, then it will check the other databases to make sure that
the structure is identical and if not, it will change them to make them
identical. Is there a program already out there that would do this? Or is
there someone out there that can help me to write it?

Thanks
Steve