Async Load Google Remarketing Javascript Module

// This module can be used to trigger the Google Adwords remarketing tag asynchronously, without loading unused ressources
// Mostly useful when the Google Remarketing tag is triggered only on specific conditions.
// Author : Vincent Hsu -> twitter.com/suisseo -> http://www.suisseo.ch
// Language : Javascript
// Usage : googremarketing.loadTag(conversionid, conversionlabel)

// Start Google Remarketing Module
var googremarketing = (function() {
    var asyncload = 0;
    // Load Async Google Adwords remarketing code
    function Gremloader() {
            if (asyncload == 0) {
                var g = document.createElement('script');
                var s = document.getElementsByTagName('script')[0];
                g.src = 'https://www.googleadservices.com/pagead/conversion_async.js';
                s.parentNode.insertBefore(g, s);
                asyncload = 1;
            }
        }
    // Wait...
    function whenAvailable(name, callback) {
            var interval = 20; // ms
            window.setTimeout(function() {
                if (window[name]) {
                    callback(window[name]);
                } else {
                    window.setTimeout(arguments.callee, interval);
                }
            }, interval);
        }
    //Set Google Remarketing Tag
    function setTag(convid, convlabel) {
        window.google_trackConversion({
            google_conversion_id: convid,
            google_conversion_label: convlabel,
            google_remarketing_only: true
        });
    }
    return {
        loadTag: function(conversionid, conversionlabel) {
            Gremloader();
            whenAvailable("google_trackConversion", function(t) {
                setTag(conversionid, conversionlabel);
            });
        }
    }
}());
// End of Google Remarketing module