function adaugareImagine($img, $user_id) {
    $link = conectare_bd();
    $img = testData($img);
    $user_id = testData($user_id);
    $img = mysqli_real_escape_string($link, $img);
    $user_id = mysqli_real_escape_string($link, $user_id);
    $query = "insert into images values(NULL, '$img', $user_id)";
    return mysqli_query($link, $query);
}