Custom Headers and Signalr: Asp.Net MVC4 Web Api

I am using signalr (version 2.0.0) in my asp.net mvc4 webapi project, Here to allow cross origin resource sharing, i use the following code in webconfig file ``` <customHeaders> <add name="Access-Control-Allow-Origin" value="*" /> <remove name="X-Powered-By" /> </customHeaders> ``` Here is the client side signalr code for receiving data from server: ``` $(function () { var nodePublishingHub = $.connection.nodePublishingHub; nodePublishingHub.client.NodePublished = onNewMessage; $.connection.hub.error(function (error) { $('#messages').append('<li>' + error + '</li>'); }); $.connection.hub.url = "http://localhost:5441/signalr"; $.connection.hub.start({ transport: 'longPolling' }) }); ``` I am using the following code to enable CORS with signalr, ``` public void Configuration(IAppBuilder app) { app.Map("/signalr", map => { map.UseCors(CorsOptions.AllowAll); var hubConfiguration = new HubConfiguration { EnableJSONP = true }; map.RunSignalR(hubConfiguration); }); } ``` However error occurs, ``` XMLHttpRequest cannot load http://localhost:5441/signalr/negotiate?connectionData=%5B%7B%22name%22%3A%…name%22%3A%22nodepublishinghub%22%7D%5D&clientProtocol=1.3&_=1386654835296. The 'Access-Control-Allow-Origin' header contains the invalid value 'null, *'. Origin 'null' is therefore not allowed access. ``` How can i solve this issue? Please help. I tried the following, I added this code in golbal.asax but it only makes each method cros enaled, so i couldnt get images from server to process. ``` HttpContext.Current.Response.Headers.Add("Access-Control-Allow-Origin", "*"); ```