gistfile1.html

<div id="rb-follow-button"></div>
	<script>
	    window.twttr = (function (d,s,id) {
			var t, js, fjs = d.getElementsByTagName(s)[0];
			if (d.getElementById(id)) return; js=d.createElement(s); js.id=id;
			js.src="https://platform.twitter.com/widgets.js"; fjs.parentNode.insertBefore(js, fjs);
			return window.twttr || (t = { _e: [], ready: function(f){ t._e.push(f) } });
		}(document, "script", "twitter-wjs"));

		twttr.ready(function(twttr){
			twttr.widgets.createFollowButton(
				'designwall_com', //screen_name 
				document.getElementById('rb-follow-button'), //target,
				function( args ) {
				} //Callback after button was rendered

			);

		    twttr.events.bind('follow', function (event) {

		  		var followed_user_id = event.data.user_id;

		  		var followed_screen_name = event.data.screen_name;
		  		console.log( 'Followed: ' + followed_user_id );

			});

			twttr.events.bind('unfollow', function (event) {

		  		var followed_user_id = event.data.user_id;

		  		var followed_screen_name = event.data.screen_name;
		  		console.log( 'Unfollowed: ' + followed_user_id );

			});
		});
	</script>