<system.webServer>

    <handlers>

      <remove name="ExtensionlessUrlHandler-Integrated-4.0" />

      <remove name="OPTIONSVerbHandler" />

      <remove name="TRACEVerbHandler" />

      <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />

    </handlers>

    <httpProtocol>

      <customHeaders>

        <!--<add name="Access-Control-Allow-Origin" value="http://xxx.com, http://yyy.com" />-->

        <add name="Access-Control-Allow-Origin" value="*" />

        <add name="Access-Control-Allow-Methods" value="GET, POST, PUT, DELETE" />

      </customHeaders>

    </httpProtocol>

  </system.webServer>