JQuery invoke remote webservice

Sending the Access-Control-Allow-Origin header allows basic cross-origin access, but calling ASP.NET services like ASMX ScriptServices, ASPX page methods, and WCF services with AspNetCompatibilityRequirements enabled requires your site to respond with one additional CORS header: Access-Control-Allow-Headers

You can configure the same in web.config as follows,

<system.webServer>
  <httpProtocol>
    <customHeaders>
      <add name="Access-Control-Allow-Origin" value="*" />
      <add name="Access-Control-Allow-Headers" value="Content-Type" />
    </customHeaders>
   </httpProtocol>
</system.webServer>