# Javascript If you want to add some custom Javascript code, `app/assets/javascripts/custom.js` is the file to do it. For example to create a new alert just add: ```js $(function(){ alert('foobar'); }); ``` If you work with Coffeescript code you can check it with [coffeelint](http://www.coffeelint.org/) (install with `npm install -g coffeelint`) : ```bash coffeelint . ```