node server hosted on heroku not serving socket.io file

So I've made a multiplayer space shooter using node.js, socket.io and kineticJS. My Node.js server does not actually serve the client's page. My client-side files are currently hosted in a local Apache server on my computer.

The node server is up and running on Heroku right now and I can't seem to be able to get socket.io loaded on the client-side. I keep getting the "io is not defined" error. This is how I import the script:

    <script src="http://xxx-xxx-xxxx.herokuapp.com:5000/socket.io/socket.io.js"></script>

I have followed the instructions shown here: https://devcenter.heroku.com/articles/nodejs And my package.json file looks like this:

    {
    "name": "Grid-Frontier",
    "version": "0.0.1",
    "dependencies": {
      "socket.io": "0.9.x"
    },
    "engines": {
       "node": "0.6.x"
    }
    }

On localhost everything is fine and I can just do the following:

    // Importing on client side
    <script src="http://localhost:8080/socket.io/socket.io.js"></script>

    // Server-side
    server.listen(8080);
    socket = io.listen(server);