jquery kind of cron job :P

jquery_cron_job

// CHECK NEW MESSAGES (CRON)
(function checkNewMessages() {
	$.ajax({
		url: "<?=site_url('message/process')?>",
		type: 'post',
		data: {'job': 'checkNewMessages'},
		success: function(data) {
			//console.info(data);
			var data = $.parseJSON(data);
			//console.info(data);

			if(data.info == 'success')
			{
				//alert(data.result);
				if($('#counter').length > 0)
				{
					$('#counter').html(parseInt(data.result));
				}
			}
			else
			{
				if($('#counter').length > 0)
				{
					$('#counter').html('');
				}
			}
		},
		complete: function() {
			// Schedule the next request when the current one's complete
			setTimeout(checkNewMessages, 5000);
		}
	});
})();