$id_tr = $_POST['id_tr'];
extract($_POST);
$yyy = (count($_POST)) / 4;
for ($i = 0; ; $i++) {
if ($i == $yyy ) {
break;
} else {
$sql = "INSERT INTO wow (id_tr, day_no, day_title, day_desc)
VALUES ('$id_tr', '${"day_no".$i}', '${"day_title".$i}', '${"day_desc".$i}')";
$conn->query($sql);
}
}