اینا هم کدهای صفحه check.php هست
<?php
include 'db.php';
$un=$_POST['un'];
$pw=$_POST['pw'];
$s=mysqli_query($conn,"select * from user where username='$un' && password='$pw'");
$user_info=mysqli_fetch_array($s);
var_dump($user_info);
$d=mysqli_num_rows($s);
if($d==0)
{
echo "notfound";
}
else{
session_start();
$_SESSION['user_logged']= $user_info['id'];
echo "found";
}
?>