Code: http://codepen.io/mjau-mjau/pen/yDKBh/ What is the "jQuery" keyword at the end of the first function on line 142... }(jQuery, this, this.document)); I think my javascript isn't working because this variable is undefined. What am I supposed to do with this?
The code you are demo'ing has // mtree.js // Requires jquery.js and velocity.js (optional but recommended). which means you need to have the jquery library uploaded and linked - and you should have velocity too jquery is an amazing library that makes working with javascript much easier for those who dip in and out of the code. Arguably it slows down load times, is bloated etc but it has become an industry mainstay.