Problem med upload script

Hej.
Jeg arbejder normalt i ASP, men skulle bruge et PHP upload script så er lidt lost i koden. :-)

Har fundet dette script og rettet det til, men det kan kun uploade billede filer, hvilket også virker fint.
Jeg skal bruge den til .flv filer (flash) men der skriver den blot filen er "empty". Nogen der kan hjælpe med at rette det til så det også virker med andre filer?

Mvh.
Henrik


od="post" enctype="multipart/form-data" action="<?= $_SERVER['PHP_SELF'] ?>">
<input type="hidden" name="action" value="upload">
Upload file!
<input type="file" name="userfile">
<input type="submit" name="submit" value="Upload">
</form>
<?php
}

function upload_file() {
$userfile = $_FILES['userfile']['tmp_name'];
$userfile_name = $_FILES['userfile']['name'];
$userfile_size = $_FILES['userfile']['size'];
$userfile_type = $_FILES['userfile']['type'];
$userfile_dim = getimagesize($_FILES['userfile']['tmp_name']);

$archive_dir=$_SERVER['DOCUMENT_ROOT']."/flashfiler/";

$filename = basename($userfile_name);
$max_filesize = 50000000;
if($userfile_size <= 0) die ("$filename is empty");
if($userfile_dim[0] > 2000 || $userfile_dim[1] > 2000) die("Image over 200x200 px!");

if($userfile_size > $max_filesize) die ("$filename is too big! Only $max_filesize bytes allowed!");
if(!move_uploaded_file($userfile, "$archive_dir/$filename")) die ("Can't copy $userfile_name to $filename.");

echo "<img src=\"upload/$filename\"><br>";
echo "$filename has been successfully uploaded.<br>";
echo "Filesize: " . number_format($userfile_size) . "<br>";
echo "Filetype: $userfile_type<br>";
}
?>
<?php
if($_POST['action'] == 'upload') {
upload_file();
} else {
upload_form();
}
?>