A simple function that simplifies script injection

injectJS.js

var injectJS = function(uri){
    var _injectJS_script = document.createElement("script");
    _injectJS_script.src = uri;
    document.querySelectorAll("head")[0].appendChild(_injectJS_script);
}

// injectJS("//ajax.googleapis.com/ajax/libs/mootools/1.4.5/mootools-yui-compressed.js")