Async JS Lib Load

async-js-lib-load.js

(function(window, document){
	var load = function(){
		var script = document.createElement('script');
		script.async = true;
		script.type = 'text/javascript';
		script.src = 'THE_SOURCE_OF_JS_LIB_HERE.js';
		var firstScript = document.getElementsByTagName('script')[0];
		firstScript.parentNode.insertBefore(script, firstScript);
	};
	if(document.readyState === "complete"){
		load();
	}else if(window.attachEvent){
		window.attachEvent('onload', load);
	}else{
		window.addEventListener('load', load);
	}
})(window, document);