Aiuto su upload multiplo

[fermat]

adesso funziona quasi tutto tranne il fatto che mi carica solo una foto:

// form di upload 
       <form action="check_image.php" method="post" enctype="multipart/form-data">
            <table>
                <tr>
                    <td>Upload: </td>
                </tr>
                <tr>
                    <td><input type="file" name="file[]" /></td>
                </tr>
                <tr>
                    <td><input type="file" name="file[]" /></td>
                </tr>
                <tr>
                    <td>Caption: </td>   
                </tr>
                <tr>
                    <td><input type="text" name="caption" /></td>
                </tr>
                <tr>
                    <td>Category: </td>
                </tr>
                <tr>
                    <td>
                        <?php
                        include_once 'config.php';
                        $query = "select * from category order by title asc";
                        $result = mysql_query($query) or die(mysql_error($link));
                        echo '<select name="category">';
                        echo '<option value="javascript:void(0)">Scegli la categoria</option>';
                        while ($riga = mysql_fetch_array($result)) {
                            echo "<option value=" . $riga['title'] . ">" . $riga['title'] . "</option>";
                        }
                        echo '</select>';
                        echo '

';
                        ?>
                    </td>
                </tr>
                <tr>
                    <td><input type="submit" name="upload" value="Upload" /></td>
                </tr>
            </table>
        </form>

// check_image.php
include_once 'config.php';
$maxSize = 500; //massima dimensione dei file in kilobyte
$acceptType = array(//tipi di file accettati, in questo caso solo immagini
    'png' => 'image/png',
    'jpe' => 'image/jpeg',
    'jpeg' => 'image/jpeg',
    'jpg' => 'image/jpeg',
    'gif' => 'image/gif',
    'bmp' => 'image/bmp',
    'ico' => 'image/vnd.microsoft.icon',
);
$cartella = "images/"; //cartella dove vengono caricati i file nel server
$image_caption = $_POST['caption'];
$image_category = $_POST['category'];
$image_date = date('Y-m-d');
$query = 'insert into images (image_caption,image_date,image_category) values ("' . $image_caption . '","' . $image_date . '","' . $image_category . '")';
$result = mysql_query($query, $db) or die(mysql_error($db));
for ($i = 0; $i < count($_FILES['file']['name']); $i++) {
    echo "Risultato file " . ($i + 1) . ": " . singleUpload($i, $cartella, $maxSize, $acceptType) . "
";
}

function singleUpload($i, $cartella, $maxSize, $acceptType) {
    if ($_FILES['file']['name'][$i] != "") {
//        $destinazione = $cartella . basename($_FILES['file']['name'][$i]);
        $destinazione = $cartella . basename(mysql_insert_id() . "_" . $_POST['category'] . '.jpg');
        if ($_FILES['file']['size'][$i] <= $maxSize * 1024) {// da levare appena il resto funziona
            if (in_array($_FILES['file']['type'][$i], $acceptType)) {
                if (move_uploaded_file($_FILES['file']['tmp_name'][$i], $destinazione)) {
                    return "File caricato con successo!";
                } else {
                    return "Errore nell'upload del file";
                }
            } else {
                return "Tipo di file non accettato!";
            }
        } else {
            return "Dimensione del file troppo grande, massima dimensione accettata: " . $maxSize . " kilobyte";
        }
    } elseif (isset($_POST['upload'])) {
        return "Nessun file inserito!";
    }
}