function muda_mes( month, year )
{
	document.getElementById("calendario").innerHTML = "<img src=\"images/ajax-loader.gif\">";
	
	http.open("GET", "includes/muda_mes.php?month=" + month + "&year=" + year, true);
	http.onreadystatechange = function() {
		handleHttpResponse('calendario')
	}
	http.send(null);
}