So I've been trying to connect my javascript webapp to github's API via a server proxy (to hide the `client_secret`) but I noticed that while I can make HTTP requests (GET,POST etc), I'm not able to do them through my webapp. The server resides in the following url: `http://mydomain.com:3000` while my webapp is at `http://mydomain.com`. When I'm trying to use JQuery's `$.ajax` to do a `POST`, I'm getting the following error:

```
No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://mydomain.com' is therefore not allowed access.

```

So my question is whether a request to a different port but in the same domain name is considered a cross-origin request