Application not connecting to Gateway system

Hello,

I have developed an HTML & Javascript application to consume a NetWeaver Gateway service, based on the below tutorial:

http://www.sdn.sap.com/irj/scn/go/portal/prtroot/docs/library/uuid/505619a7-73bf-2e10-fe96-da9a86b23120?QuickLink=index&overridelayout=true&52239688165884

I have hosted the HTML & Javascript files on the same server as the Gateway system(using remote desktop). So I should not need a Web server configured as a reverse proxy.

However, on running the HTML application on the Gateway server, it gives the following error:

XMLHttpRequest cannot loadhttp://<GW server host>:<GW server port>/sap/opu/odata/sap/Z_…=100&sap-user=*****&sap-password=***&sap-language=EN. Origin null is not allowed by Access-Control-Allow-Origin.

However, the url in itself works fine and shows the Gateway service response in a browser.

Any inputs on what may be missing?

Is there some configuration on the Gateway system that prevents it from sending data back to the HTML app?

Regards,

Sudeep