<?php
$user= $_POST['username'];
$pass=$_POST['password'];

$user= stripcslashes($user);
$pass= stripcslashes($pass);

$user= mysql_real_escape_string($user);
$pass= mysql_real_escape_string($pass);

session_start();
$_SESSION['sid']=  session_id();

$servername= "localhost";
$username= "root";
$password="";
$database="lottery";

$conn= mysql_connect($servername, $username, $password, $database);
mysql_select_db($database);
if(!$conn)
{
    die("Connection Failed" .mysqli_connect_error());
}

$result= mysql_query("Select * from login where username= '$user' and password='$pass'")
        or die("Failed To query database" .  mysql_error());
$row= mysql_fetch_array($result);
if($row['username']== $user && $row['password'] == $pass)
{
    header('Location: ad.php');
}
 else {

    echo"<h2 style='text-align: center'>Invalid Username or Password</h2>";
    ?> <h3 style="text-align: center">For Login again please <a href="login.php">Click</a> here</h3>
<?php
}
?>