Unable to rename a file while upload

Hello,

I want to rename files, images etc... using PHP because the contains (many times) invalid chars.

For exemple the file :
test é è ê à 1.txt should be renamed as : test_e_e_e_a_1.txt

So in the file FileUpload.php I changed :

 $sFileName = str_replace(array(":", "*", "?", "|", "/", " "), "_", $sUnsafeFileName);

by

 
 $sFileName = str_replace(array(":", "*", "?", "|", "/", " ", "  ", "é"), "_", $sUnsafeFileName);
 $sFileName = str_replace(array("é", "è", "ê"), "e", $sFileName );

But it change nothing.

Have you got an idea ?!

Thanks !

PS : souldn't it be done directly by ckfinder ?