enter code here

require_once('db.php');

    $sql = 'SELECT * FROM users_table
                WHERE username="'.mysql_escape_string($uname).'" AND password="'.mysql_escape_string(md5($pw)).'"
            LIMIT 0, 1
    ';
    $qry = mysql_query($sql);
    $count = mysql_num_rows($qry);

    if($count > 0) {
        $_SESSION['username'] = $uname;
        $_SESSION['password'] = $pw;
        header('Location: products_list.php');
    } else {
        header('Location: index.php?error=1');
    }
}