login dot php

<?php

$host="mysql.hostinger.co.uk";
$admin_user="u344373728_steve";
$admin_pass="xadera007";
$db="u344373728_log";
$user=$_POST["username"];
$pass=$_POST["password"];

$validated=false;

session_start();
$_SESSION['login']="";
if($user!=""&&$pass!="")
    {
      $conn=@mysql_connect($host,$admin_user,$admin_pass) or die ("Sorry- unable to connect to MySQL database.");
       $rs=@mysql_select_db("$db",$conn) or die("error");
           $sql="SELECT*FROM log WHERE username='$user' AND password='$pass'";
       $rs=mysql_query($sql,$conn);
       $result=mysql_num_rows($rs);
if($result>0)$validated=true;



    if($validated)

{

$_SESSION['login']="OK";

$_SESSION['username']=$user;

$_SESSION['password']=$pass;

 header('Location:protected.php');
}

else

{
    $_SESSION['login']="";

echo"Invalid username or password.";

}

    }

?>