How to have script check for updates?

I have a program that I made for work that I periodically have to make changes to/fix bugs. What is the best approach to give it the ability to update itself.

My initial though is since it already uses ftp connection for uploading data to have a directory in the ftp site setup that will hold the latest software revisions and that it would check if there were a newer version. Automatically upon start it would give the user the option to update it.

Also, the script is actually converted into a .exe file for distribution to other computers.

Any suggestion would be helpful. Thank you.

I think your proposal makes sense, and that you should try to implement something first and see if you have a more specific question after that.