function ajax(str, id, f)
{
	if (window.XMLHttpRequest)
	{// codice per IE7+, Firefox, Chrome, Opera, Safari
		xmlhttp = new XMLHttpRequest();
	}
	else
	{// codice per IE6, IE5
		xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
	}
	xmlhttp.onreadystatechange = function()
	{
		if (xmlhttp.readyState == 4 && xmlhttp.status == 200)
		{
			document.getElementById(id).innerHTML = xmlhttp.responseText;
		}
	}
	xmlhttp.open("GET","../ajax.php?f="+f+"&q="+str+"&id="+id, true);
	xmlhttp.send();
}