Yii 的Web Service的一个问题，求解！ [ 新手入门 ]

我是按照官方说明一步一步的做Web Service 但是当我用

$client=new SoapClient('http://hostname/path/to/index.php?r=stock/quote');
echo $client->getPrice('GOOGLE');

去访问我这个webservice的时候出现如下错误，如何解决啊！ Fatal error: Uncaught SoapFault exception: [Client] Function ("getPrice") is not a valid method for this service in E:\wamp\www\index.php:3 Stack trace: #0 [internal function]: SoapClient->__call('getPrice', Array) #1 E:\wamp\www\index.php(3): SoapClient->getPrice('GOOGLE') #2 {main} thrown in E:\wamp\www\index.php on line 3