PHP file/pic upload - download

<?
if(isset($_GET['f']))
{
    require_once 'db.php';
    require_once 'banlist.php';
    $upid = $_GET['f'];
    $query = MySQL_Query("SELECT * FROM `files` WHERE id='$upid'") or die (mysql_error());
    while($result = mysql_fetch_array($query))
    {
        $soubor="upload/".$result['url'];
        $nazev=$result['nazev'];
    }
    $pripona = strtolower(pathinfo($soubor, PATHINFO_EXTENSION));
    if(isset($nazev))   $name=$nazev;
    else                $name = "justDownloaded.".$pripona;
    header("Content-Description: File Transfer");
    header("Content-Type: application/force-download");
    header("Content-Disposition: attachment; filename=\"$name\""); //jmeno souboru po stazeni
    readfile($soubor);
}
?>