Arkadaşlar form ile resmi alıp kaydetmek ve thumbnail oluşturmak istiyorum ama nedense kayıt yapamıyorum. Koddaki hata nerede bakabilir misiniz?

if (isset($_POST['image'])) {


$filename = $_FILES['image']['name'];
$temporary_name = $_FILES['image']['tmp_name'];
$mimetype = $_FILES['image']['type'];
$filesize = $_FILES['image']['size'];
switch($mimetype) {
    case "image/jpg":
    case "image/jpeg":
        $i = imagecreatefromjpeg($temporary_name);
        break;
    case "image/gif":
        $i = imagecreatefromgif($temporary_name);
        break;
    case "image/png":
        $i = imagecreatefrompng($temporary_name);
        break;
}
unlink($temporary_name);
$zaman=time();
imagejpeg($i,"answers/cevap$time.jpg",90);

$dest_x = 200;
$dest_y = 200;
if (imagesx($i) > $dest_x or imagesy($i) > $dest_y) {
    if (imagesx($i) >= imagesy($i)) {
        $thumb_x = $dest_x;
        $thumb_y = imagesy($i)*($dest_x/imagesx($i));
    } else {
        $thumb_x = imagesx($i)*($dest_y/imagesy($i));
        $thumb_y = $dest_y;
    }
} else {
    $thumb_x = imagesx($i);
    $thumb_y = imagesy($i);
}
$thumb = imagecreatetruecolor($thumb_x,$thumb_y);
imagecopyresampled($thumb, $i ,0, 0, 0, 0, $thumb_x, $thumb_y, imagesx($i), imagesy($i));
imagejpeg($thumb, "answers/thumb_$time.jpg", 90);





}