<?php
   session_start(); // Starting Session
   $error=''; // Variable To Store Error Message
   if (isset($_POST['submit'])) {
       if (empty($_POST['username']) || empty($_POST['password'])) {
           $error = "Username or Password is invalid";
       } else {
           // Define $username and $password
           $username=$_POST['username'];
           $password=$_POST['password'];
           // To protect MySQL injection for Security purpose
           $username = stripslashes($username);
           $password = stripslashes($password);
           $username = mysqli_real_escape_string($username);
           $password = mysqli_real_escape_string($password);
           // Selecting Database
           $mysqli = new mysqli("localhost", "root", "root");
           $mysqli->select_db('tasty_recipe') or die ($mysqli->error);
           // SQL query to fetch information of registerd users and finds user match.
           $sql = $mysqli->query("SELECT * FROM `user` WHERE password='$password' AND username='$username'") or die ($mysqli->error);
           if ($sql->num_rows == 1) {
               $data = $sql->fetch_assoc();
               $_SESSION['username'] = $data['username']; // Initializing Session
               header("location: profile.php"); // Redirecting To Other Page
           } else {
               $error = "Username or Password is invalid";
           }
           mysqli_close($connection); // Closing Connection
       }
   }
?>