//Javascript
$(document).ready(function() {
	setInterval(evilCounter, 20000);
});

function evilCounter() {
	$('div#counter').stop().animate({opacity: 0}, 100, function() {
		$.post('evilcounter.php', '', function(data) {
			$('div#counter').html(data).stop().animate({opacity: 1}, 100);
		});
	});
}

//PHP "evilcounter.php"

<?php
$current = @file_get_contents('evil.txt');
$fp = @fopen('evil.txt', 'w');
@fwrite($fp, ($current + 1));
@fclose($fp);
echo $current;
?>