All right, I found the solution now, to:to C:\inetpub\wwwroot\ArcGIS\rest\Web.ConfigI inserted <httpProtocol> <customHeaders> <add name="Access-Control-Allow-Origin" value="*" /> </customHeaders> </httpProtocol>Then it`s important that the browser supports CORS (http://enable-cors.org/)I had no Luck with Firefox 24, but it worked with Chrome 30, everything fine now 🙂