Issue in WCF named pipes

Hi all i am developing a WCF service and my requirement is to create a service with support for named pipes. I created a empty asp.net site and selected the WCFService option from the project templates.

i have given all the configuartion entries and when i try to run it it is throwing me errors saying

"The contract name 'IMetadataExchange' could not be found in the list of contracts implemented by the service DataService.  Add a ServiceMetadataBehavior to the configuration file or to the ServiceHost directly to enable support for this contract"

here is my config file:

<system.serviceModel>
    <services>
      <service behaviorConfiguration="returnFaults" name="DataService">
        <endpoint binding="netNamedPipeBinding" address ="net.pipe://localhost/DataService/Service.svc"
         bindingConfiguration="Binding1" contract="IDataService" />
        <endpoint address="mex"
          binding="mexNamedPipeBinding" bindingConfiguration="" contract="IMetadataExchange"/>
      </service>
    </services>
    <bindings>
    <netNamedPipeBinding>
      <binding name="Binding1" >
        <security mode = "None">
        </security>
      </binding >
    </netNamedPipeBinding>
  </bindings>
    <behaviors>
      <serviceBehaviors>
        <behavior name="returnFaults" >
          <serviceDebug includeExceptionDetailInFaults="true" />
      </behavior>
      </serviceBehaviors>
    </behaviors>
  </system.serviceModel>

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