function login($username,$password) {
        if($_POST["login"]) {
        $sql = "SELECT * FROM users WHERE username = '".esc($_POST["username"])."'";
        $res = mysql_query($sql);
        $row = mysql_fetch_object($res);
            $row->username = $user;
            $row->password = $pass;

        if($username == strtolower(trim($user)) && $password == trim(sha1($pass))) {
                    $_SESSION["username"] = $username;
                    setcookie("username", $username);
            }
            elseif(mysql_num_rows($res) < 1) {
                echo "Login failed!";
                }
        }

}