Upload files and special characters problem

Hi,
I’ve got a script to upload images by users. What happens is users usually put special characters on filename like “ç” and “ã”. When they do so the filename on server gets weird like this “canóú.jpg”. I would like to have some help on this script to remove this special charactres from filename on upload.
Here is the script I got:


//Send Images

$userfile2=(isset($_FILES['userfile']['tmp_name']) ? $_FILES['userfile']['tmp_name'] : "");
$userfile_name=(isset($_FILES['userfile']['name']) ? $_FILES['userfile']['name'] : "");
$imagesize = $_FILES['userfile']['size'];

if (( $imageenabled == 2 ) || ( ($imageenabled == 1) && (!empty($userfile_name)) ) ) {
$base_Dir = ELPATH.'/images/eventlist/events/';
$sizelimit = $sizelimit*1024; //size limit in kb

if ($imagesize > $sizelimit) {
mosRedirect("index.php?option=$option&Itemid=$Itemid", "Image too big"." ");
}

if (!move_uploaded_file ($_FILES['userfile']['tmp_name'],$base_Dir.$_FILES['userfile']['name']) || !mosChmod($base_Dir.$_FILES['userfile']['name'])) {
mosRedirect("index.php?option=$option&Itemid=$Itemid", _EVENTS_IMAGEFAIL." ");
} else {
$file = $base_Dir.$userfile_name;
//chmod Bild
@chmod ($file, octdec($imagechmod));
//Vorbereiten auf Thumbnailerstellung
$thumbdir = $base_Dir.'small/';
$save = $thumbdir.$userfile_name ;
if ($imageprob = 1) {
$imageprob = TRUE;
} else {
$imageprob = FALSE;
}
if ($gddisabled == 1) {
evlist_imgd::thumb($file, $save, $imagewidth, $imagehight, $imageprob);
}
}
$_POST['datimage'] = $userfile_name ;
}


Thank you for your time!

don’t use the filename provided by the user. Make your own.

Thank you for your answer.
Could be a solution as the name of image is not really important.
So, what code should I use to achieve this?
(The issue here is that images with special characters don’t show up on the site.)