Could not Store French Accent Marks Correctly in Postgres

Hi,

I'm having a problem right now. Some of our French users uploaded some files with file names that had French accent marks, and those file names were inserted into the Postgres database. When I examined the value of those file names, they all had some weird characters (the weird characters were in the same position where the accent marks were entered). I do not know how to handle this kind of situation. Most of my users are US based, but I have been told that there will be more international users in the future.

So my questions are:
(1) What is the best character encoding that would work for most of those languages that have accent marks?
(2) I assume that I also need to do some kind of conversion in the front end (PHP) as well.

I'm running on Linux and Postgres 8.3.8.

Any ideas?

Thanks in advance.
Mary Wang