World English Institute

 <?php session_start(); // ----- DATABASE CONFIG ----- $conn = mysqli_connect("localhost","root","","wei_db"); if(!$conn){ die("DB Error: ".mysqli_connect_error()); } // ----- LOGIN ----- if(isset($_POST['login'])){     $user = $_POST['user'];     $pass = $_POST['pass'];     $res = mysqli_query($conn,"SELECT * FROM users WHERE name='$user' AND password='$pass'");     if(mysqli_num_rows($res)>0){         $row = mysqli_fetch_assoc($res);         $_SESSION['user'] = $row['name'];         $_SESSION['role'] = $row['role'];         header("Location: index.php");         exit();     } else { $error = "Wrong username or password!"; } } // ----- LOGOUT ----- if(isset($_GET['logout'])){     session_destroy();     header("Location: index.php");     exit(); } // ----- ADMIN: CREATE LESSON ----- if(isset($_POST[...