var req;

function navigate(month,year) {
	var url = "_php/agenda,calendario.php?month="+month+"&year="+year;
    if(window.XMLHttpRequest) {
      	req = new XMLHttpRequest();
    }else if(window.ActiveXObject) {
        req = new ActiveXObject("Microsoft.XMLHTTP");
    }
    req.open("GET", url, true);
    req.onreadystatechange = callback;
    req.send(null);
}

function callback() {        
    obj = document.getElementById("calendario1");
    setFade(0);
        
	if(req.readyState == 4) {
    	if(req.status == 200) {
        	response = req.responseText;
            obj.innerHTML = response;
            fade(0);
        }else{
            alert("Houve um problema ao recuperar a data:\n" + req.statusText);
        }
    }
}

function fade(amt) {
	if(amt <= 100) {
		setFade(amt);
		amt += 10;
		setTimeout("fade("+amt+")", 5);
    }
}

function setFade(amt) {
	obj = document.getElementById("calendario1");
	
	amt = (amt == 100)?99.999:amt;
  
	// IE
	obj.style.filter = "alpha(opacity:"+amt+")";
  
	// Safari<1.2, Konqueror
	obj.style.KHTMLOpacity = amt/100;
  
	// Mozilla and Firefox
	obj.style.MozOpacity = amt/100;
  
	// Safari 1.2, newer Firefox and Mozilla, CSS3
	obj.style.opacity = amt/100;
}