Module not found in node-webkit

I recently started to play with node-webkit and tried to create a simple HelloWorld + load a module. The module I chose to test was the 'getmac' (https://www.npmjs.org/package/getmac).

This is my code:

<!DOCTYPE html>
<html>
  <head>
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
    <script>
    var gm = require('getmac');
    </script>
    <title>Hello World!</title>
  </head>
  <body>
    <h1>Hi!</h1>
    We are using node.js <script>document.write(process.version)</script>.
  </body>
</html>

I installed the module normally with npm install and there is a node_modules folder inside my app folder. ALL MY RESOURCES are inside the folder (there are no other folders, except for node_modules -> that means no tree structure). When I run this code I get a "module not found" error. I also read something about re-building modules with nw-gyp but I don't even know if it's necessary in this case (please include something about this in the answer if possible).
Anyway, thanks for all the help.
NOTE: the helloworld DOES work without trying to load the module.

You need to use browserify to generate the correct js file to load in the browser. From the getmac page it looks like it should support it. Here's how you can generate the js file.

The problem was when zipping everything. There was no error with the module. I forgot to add the -r when zipping, therefore the subdirs were not included.