DYNAMICALLY ADD SCRIPT ELEMENT

<!doctype html>
<html>
	<head>
		<style>
			/* CSS comes here */
			
		</style>
		<title>My App</title>
	</head>
	<body>
		Dynamic Script element demo!


		<script>
		function loadScript(url, callback)
		{
			// add the script element to the head as suggested before
			var head = document.getElementsByTagName('head')[0];
			var script = document.createElement('script');
			script.type = 'text/javascript';
			script.src = url;

			// bind the event to the callback function
			script.onreadystatechange = callback;
			script.onload = callback;

			// Append script tag in head elemn
			head.appendChild(script);
		}

		var myCode = function() {
			var g = new Greetings("Sam", "Smith", "en");
			g.greetUser();
		};

		loadScript("https://raw.githubusercontent.com/naitik0212/Greetings.js/master/Greetings.js", myCode);
		</script>
	</body>
</html>