<?php
session_start();
if (!isset($_SESSION['loggedin'])) {
    exit("unauthorized");
}

include "../database.php";

$month = $_POST["month"];

$sql = "SELECT * FROM attendance WHERE month = '$month'";
$result = mysqli_query($con, $sql);
if ($result->num_rows > 0) {
    echo "error";
} else {
    echo "ok";
}

$con->close();