Dumb Question - Replacement Door & Lock

[edinburghman]

Hi,

Can anyone help? The driver's door of my 2001 Ford Focus is rather rusty at the bottom so I'm thinking of buying a replacement door and fitting it myself - it looks reasonably easy to do.

However, what about the locks in the door? Do I need to somehow switch the locks from the old door into the replacement door? Or does the new door miraculously work with my old keys because the electrics tell it to?

Thanks for any help.

Ian