Lazy load js from TinyDOM - https://github.com/ctult/TinyDOM/blob/master/tinyDOM.js

jsLazyLoad.js

//Able to load a JS file
$.loadJS = function (src) {
    var s = document.createElement('script')
    s.type = 'text/javascript'
    s.async = true
    s.src = src
    var x = document.getElementsByTagName('script')[0]
    x.parentNode.insertBefore(s, x)
}