<form class="follow-form" method="post" action="twitter-follow.php">
	<input type="hidden" name="followID" value="123456">
	<button type="submit" value="Actions" class="btn follow" title="123456">
		<i></i><span>follow</span>
	</button>
</form>

/* with mootools */
window.addEvent('domready',function() {
	/* fetch elements */
	$$('form.follow-form').each(function(form) {
		/* stop form event */
		form.addEvent('submit',function(e) {
			/* stop event */
			if(e) e.stop();
			/* send ajax request */
			var i = form.getElement('i');
			new Request({
				url: 'twitter-follow.php',
				method: 'post',
				data: {
					followID: form.getElement('input').value
				},
				onRequest: function() {
					i.addClass('active');
				},
				onSuccess: function() {
					var button = form.getElement('button');
					button.setStyle('display','none');
					new Element('span',{
						html: '<span></span>Following!',
						'class': 'following'
					}).inject(button,'after');
				},
				onComplete: function() {
					i.removeClass('active');
				}
			}).send();
		});
	});
});

// Idiomatic jQuery by Doug Neiner
jQuery(function ($) {
	/* fetch elements and stop form event */
	$("form.follow-form").submit(function (e) {
		/* stop event */
		e.preventDefault();
		/* "on request" */
		$(this).find('i').addClass('active');
		/* send ajax request */
		$.post('twitter-follow.php', {
			followID: $(this).find('input').val()
		}, function () {
			/* find and hide button, create element */
			$(e.currentTarget)
			  .find('button').hide()
			  .after('<span class="following"><span></span>Following!</span>');
		});
	});
});

* when the DOM is ready */
dojo.ready(function() {
	/* fetch elements */
	dojo.query('form.follow-form').forEach(function(form) {
		/* stop form event */
		dojo.connect(form,'onsubmit',function(e) {
			/* stop event */
			dojo.stopEvent(e);
			/* active class */
			dojo.query('i',form).addClass('active');
			/* get button */
			var button = dojo.query('button',form)[0];
			/* ajax request */
			dojo.xhrPost({
				form: form,
				load: function() {
					dojo.style(button,'display','none');
					dojo.create('span',{
						innerHTML: '<span></span>Following',
						className: 'following'
					},button,'after');
				}
			});
		});
	});
});