<?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'];

$connection = mysqli_connect("localhost", "username", "password", "dbname");

$query = mysql_real_query("select * from login where password='$password' AND username='$username'", $connection);
$rows = mysql_num_rows($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";
}

mysql_close($connection); // Closing Connection
}
}
?>