Ford Focus - At what mileage should the timing belt be changed? - 1

I'm interested in purchasing a Ford Focus between 98-04 and I was wondering does anyone know when the timing belt/cam belt should be replaced?

100k miles on the Zetec engine - also a good idea to replace the water pump at the same time.

100000 miles or 10 years whatever come first so it should have had one by 2014 at the latest. If this can't be confirmed then it will need to be changed immediately.