portType绑定wsdl解析错误

Question

I have problem with creating wsdl file for soap service. I have declarated in wsdl file

<portType name="RegistrationService">
    <operation name="registration">
        <input message="tns:registration"/>
        <output message="tns:registrationResponse"/>
        <fault message="tns:ServerException" name="ServerException" />
        <fault message="tns:ValidationException" name="ValidationException" />
        <fault message="tns:DenialOfServiceException" name="DenialOfServiceException" />
    </operation>
</portType>

And then try to use it like this

    <binding name="RegistrationBinding" type="tns:RegistrationService">
</binding>

but validator throws me

Could not find the portType definition for 'tns:RegistrationService' in the binding'RegistrationBinding'.

I can't get what's wrong with it, because i'm using and call it correctly.