forms - Symfony "Could not load type" service yaml -

i tried create service in symfony 2.2 1 of form :

service.yml:

tyg_user.settings.form:     class: symfony\component\form\form     factory_method: createnamed     factory_service: form.factory     arguments:          - tyg_user_settings         - tyg_user_settings_name tyg_user.settings.form.type:     class: tyg\userbundle\form\settings\settingsformtype     tags:         - { name: form.type, alias: tyg_user_settings } tyg_user.settings.form.handler:     class: tyg\userbundle\form\settings\settingsformhandler     scope: request     arguments:         - @tyg_user.settings.form         - @request         - @fos_user.user_manager 

settingsform.php

<?php  namespace tyg\userbundle\form\settings;  use symfony\component\form\formbuilderinterface formbuilder;; use symfony\component\form\abstracttype;  class settingsform extends abstracttype {    public function buildform(formbuilder $builder, array $options)   {       $builder         ->add('birthday', 'birthday')         ->add('email', 'email')         ->add('showmail')         ->add('showbirthday')       ;   }    public function getname()   {       return 'tyg_user_settings';   } } ?> 

but error occuered :

could not load type "tyg_user_settings_name 

this occurs when form through service container :

$this->container->get('tyg_user.settings.form'); 

i used create service through xml format when change yml format can't figure out how to make works

the tyg_user_settings_name referencing form type alias.

if wanting reference parameter should use %tyg_user_settings_name% instead.