var tooltip=function(){
	var id = 'tt';
	var top = 3;
	var left = 3;
	var maxw = 300;
	var speed = 5;
	var timer = 20;
	var endalpha = 100;
	var alpha = 0;
	var tt,t,c,b,h;
	var ie = document.all ? true : false;
	return{
		show:function(v,w){
			if(tt == null){
				tt = document.createElement('div');
				tt.setAttribute('id',id);
				t = document.createElement('div');
				t.setAttribute('id',id + 'top');
				c = document.createElement('div');
				c.setAttribute('id',id + 'cont');
				b = document.createElement('div');
				b.setAttribute('id',id + 'bot');
				tt.appendChild(t);
				tt.appendChild(c);
				tt.appendChild(b);
				document.body.appendChild(tt);
				tt.style.opacity = 0;
				tt.style.filter = 'alpha(opacity=0)';
				document.onmousemove = this.pos;
			}
			tt.style.display = 'block';
			c.innerHTML = v;
			tt.style.width = w ? w + 'px' : 'auto';
			if(!w && ie){
				t.style.display = 'none';
				b.style.display = 'none';
				tt.style.width = tt.offsetWidth;
				t.style.display = 'block';
				b.style.display = 'block';
			}
			if(tt.offsetWidth > maxw){tt.style.width = maxw + 'px'}
			h = parseInt(tt.offsetHeight) + top;
			clearInterval(tt.timer);
			tt.timer = setInterval(function(){tooltip.fade(1)},timer);
		},
		pos:function(e){
			var u = ie ? event.clientY + document.documentElement.scrollTop : e.pageY;
			var l = ie ? event.clientX + document.documentElement.scrollLeft : e.pageX;
			tt.style.top = (u - h) + 'px';
			tt.style.left = (l + left) + 'px';
		},
		fade:function(d){
			var a = alpha;
			if((a != endalpha && d == 1) || (a != 0 && d == -1)){
				var i = speed;
				if(endalpha - a < speed && d == 1){
					i = endalpha - a;
				}else if(alpha < speed && d == -1){
					i = a;
				}
				alpha = a + (i * d);
				tt.style.opacity = alpha * .01;
				tt.style.filter = 'alpha(opacity=' + alpha + ')';
			}else{
				clearInterval(tt.timer);
				if(d == -1){tt.style.display = 'none'}
			}
		},
		hide:function(){
			clearInterval(tt.timer);
			tt.timer = setInterval(function(){tooltip.fade(-1)},timer);
		}
	};
}();

function getXmlHttpRequest(){
	//crea istanza httprequest
	var httpRequest=null;
	try{
		httpRequest=new ActiveXObject("Msxml2.XMLHTTP");
	}catch(e){
		try{
			httpRequest=new ActiveXObject("Microsoft.XMLHTTP");
		}catch(e){
			httpRequest=null;
		}
	}
	if(!httpRequest&&typeof XMLHttpRequest!="undefined"){
		httpRequest=new XMLHttpRequest();
	}
	return httpRequest;
}

function updateDiv(id, url){
	//aggiorna un elemento html
	var req=getXmlHttpRequest();
	req.open("GET",url,true);
	req.onreadystatechange=function(){
		if (req.readyState==4 || req.readyState=="complete"){
			if (req.status==200){
				var el=document.getElementById(id);
				el.style.display='block';
				el.innerHTML=req.responseText;
			}
		}
	}
	req.send(null);
}

function updateSelect(id, url){
	//aggiorna un elemento html
	var el=document.getElementById(id);
	el.disabled=true;
	//elimina opzioni correnti
	var l=el.options.length;

	el.options[0]=new Option('caricamento...','',true);
	for(i=l;i>0;i--){
		el.options[i]=null;
	}

	var req=getXmlHttpRequest();
	req.open("GET",url,true);
	req.onreadystatechange=function(){
		if (req.readyState==4 || req.readyState=="complete"){
			if (req.status==200){
				if(req.responseText!=''){
					//crea array nuove opzioni
					var new_options_arr=req.responseText.split("|");
					var l=new_options_arr.length;
					el.options[0]=null;
					for(i=0;i<l;i++){
						var p=new_options_arr[i].split("_");
						el.options[i]=new Option(p[0],p[1]);
					}
				}else{
					el.options[0]=null;
				}
				el.disabled=false;
			}
		}
	}
	req.send(null);
}