<?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'];
// Establishing Connection with Server by passing server_name, user_id and password as a parameter
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "server1";
// Create connection
$conn = new mysqli($servername, $username, $password,$dbname);

// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
// To protect mysqli injection for Security purpose
$username = stripslashes($username);
$password = stripslashes($password);
$username = mysqli_real_escape_string($username);
$password = mysqli_real_escape_string($password);
// Selecting Database
$db = mysqli_select_db("server1", $conn);
// SQL query to fetch information of registerd users and finds user    match.
$query = "select * from account where password='$password' AND username='$username'";
$result = mysqli_query($conn, $query) or trigger_error("Query Failed! SQL: $query - Error: ". mysqli_error($mysqli), E_USER_ERROR);;
$rows = mysqli_num_rows($query);
if ($rows == 1) {
$_SESSION['login_user']=$username; // Initializing Session
header("location: profile.php"); // Redirecting To Other Page
} else {
$error = "Username or Password is invalid";
}
mysqli_close($conn); // Closing Connection
}
}
?>