# 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: ```javascript $(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 . ```