// параметры полученные из формы через глобальный массив $_POST и присваиваем $_SESSION['condition'] значение 3
if ($_GET['submit'] == 'Login') {
    if ($newUser->_login($_GET['login'], $_GET['password'])) {
        $_SESSION['condition'] = 3;
    }
} elseif ($_GET['submit'] == 'Registration') {
    $_SESSION['condition'] = 2;
} elseif ($_GET['submit'] == 'Register') {
    if ($newUser->register($_GET['name'], $_GET['surname'], $_GET['login'], $_GET['email'], $_GET['password'], $_GET['r_Password'])) {
        $newUser->sendCheckEmail($_GET['email']);
        $_SESSION['condition'] = 1;
    } else {
        $_SESSION['condition'] = 2;
    }
} elseif ($_GET['submit'] == 'Logout') {
    $newUser->logout();
    $_SESSION['condition'] = 1;
} elseif ($_GET['submit'] == 'EditInfo') {
    $_SESSION['condition'] = 4;
} elseif ($_GET['submit'] == 'Edit') {
    $newUser->editData($_GET['name'], $_GET['surname'], $_GET['password'], $_GET['login']);
    $_SESSION['condition'] = 3;
} elseif (!empty($_GET['confirm'])) {
    $newUser->acceptRegFromEmail($_GET['confirm']);
}
$smarty->assign('cond', $_SESSION['condition'], true);
$smarty->assign('name', $newUser->name, true);
$smarty->assign('surname', $newUser->surname, true);
$smarty->assign('login', $newUser->login, true);
$smarty->assign('email', $newUser->email, true);
$smarty->display('index.tpl');