Utf 8 to iso-8859-1?

Dear all,
'been using the email form tutorial and it works great 'till the day I used it in France where there is a difference of text encoding, apparently.
I spent a bit of time trying to find out how to trick flash into sending the email form in charset=iso-8859-1 or my email folder to transform the recieved variables into iso-8859-1.
Nothing does it at all and I get some strange signs for accents and so on…
Can anyone please help?
Thaks a lot.
Fabrice