var i = 0;
var s;
var speed = 15;
var step = 5;
var dr = 'off';
var scr = 'on';

if (window.addEventListener)
window.addEventListener('DOMMouseScroll', wheel, false);
window.onmousewheel = document.onmousewheel = wheel;

function wheel(event)
{
if ((scr=='on')&&(document.getElementById('scrollbar')!=null))
{
var delta = 0;
if (!event)
event = window.event;
if (event.wheelDelta)
{
delta = event.wheelDelta/120;
if (window.opera)
delta = -delta;
}
else if (event.detail)
{
delta = -event.detail / 3;
}
if (delta)
handle(delta);

if (event.preventDefault)
event.preventDefault();
event.returnValue = false;
}
	function handle(delta)
{
riq = parseInt(document.getElementById('testo').offsetHeight);
if((riq > 160)&&(scr=='on'))
{
if (delta < 0)
{
	step=10;
	scroll(2);
}
else
{
	step=10;
	scroll(1);
}
}
}
}

function inizializza_scroll()
{
	if(parseInt(document.getElementById('testo').offsetHeight) < 160)
	document.getElementById('scrollbar').style.visibility = 'hidden';
}


function dd_menu(tab,stato,tipo)
	{
			switch (stato)
			{
				case true:
					document.getElementById(tab).className= 'voce_dd_off';
					document.getElementById(tab + '_cx').className = 'voce_cx_off';
					if(tipo==''){document.getElementById(tab + '_sub').style.visibility='hidden';}
				break;
				
				case false:
					document.getElementById(tab).className= 'voce_dd_on';
					document.getElementById(tab + '_cx').className = 'voce' + tipo + '_cx_on';
					if(tipo==''){document.getElementById(tab + '_sub').style.visibility='visible';}
				break;
			}
	}	

function scorri(direzione,stato)
{
step = 5;
riq = parseInt(document.getElementById('testo').offsetHeight);
if(riq > 160)
	{
	switch(direzione)
	{	
	case 'su':
		switch(stato)
			{	
			case 'on':
				s = 1;
				scroll(1);
			break;
			case 'off':
				s=0;
			break;
			}
	break;
	case 'giu':
		switch(stato)
			{	
			case 'on':
				s = 1;
				scroll(2);
			break;
			case 'off':
				s=0;
			break;
			}
	break;
	}
	}
}

function scroll(direzione)
{
	var top;
	var alt;
	var c_top;
	var c_alt;
	var alt_fr = 10;

	var yMousePos = 0;
	box_h = parseInt(document.getElementById('scrollbar').offsetHeight);
	riq = parseInt(document.getElementById('txt_sx').offsetHeight);
	top = parseInt(document.getElementById('testo').offsetTop);
	alt = parseInt(document.getElementById('testo').offsetHeight);
	c_top = parseInt(document.getElementById('cursore').offsetTop);
	c_alt = parseInt(document.getElementById('scrollbar').offsetHeight) - (alt_fr * 2)  - 10;

	switch(direzione)
	{	
		case 1:
			if(Math.abs(top) <= step) 
			top = 0;
			else
			top = top + step;	
			document.getElementById('testo').style.top = top;
			document.getElementById('cursore').style.top = - ((top) * (c_alt) / (alt - riq)) + alt_fr;
		break;			
		case 2:
			if (!((-top) >= (alt - box_h))) 
			top = top - step;	
			else
			top = - (alt - box_h);	
			document.getElementById('testo').style.top = top;
			document.getElementById('cursore').style.top = - ((top) * (c_alt) / (alt - riq)) + alt_fr;
		break;		
	}
	if(s == 1) setTimeout('scroll(' + direzione + ')', speed);
}	
function drag()
{
	var alt_fr = 10;
	var box_h = parseInt(document.getElementById('scrollbar').offsetHeight);
	var riq = parseInt(document.getElementById('txt_sx').offsetHeight);
	var alt = parseInt(document.getElementById('testo').offsetHeight);
	var c_alt = parseInt(document.getElementById('scrollbar').offsetHeight) - (alt_fr * 2)  - 10;
	var c_top = 0;

	var t_top = 0;
	if(dr=='on')
	{
		document.getElementById('cursore').style.top = (yMousePos - bX + bT);
		riq = parseInt(document.getElementById('txt_sx').offsetHeight) - 20;
		if (document.getElementById('cursore').offsetTop < 10) document.getElementById('cursore').style.top = 10;
		if (document.getElementById('cursore').offsetTop > riq) document.getElementById('cursore').style.top = riq;
		c_top = parseInt(document.getElementById('cursore').offsetTop) - 10;
		t_top = - ((alt - riq - alt_fr) * c_top / c_alt);
		if(t_top < - (alt - box_h - 2)) t_top = -(alt - box_h);
		document.getElementById('testo').style.top = t_top;
	}
}
function startdrag()
{
	riq = parseInt(document.getElementById('testo').offsetHeight);
	if(riq > 160)
	{
		dr='on';
		bX = yMousePos;
		bT = document.getElementById('cursore').offsetTop;
	}
}
function stopdrag()
{
	dr='off';
}

function startscroll(){scr='on'}
function stopscroll(){scr='off'}

if (document.layers) {
    document.captureEvents(Event.MOUSEMOVE);
    document.onmousemove = captureMousePosition;
} else if (document.all) {
    document.onmousemove = captureMousePosition;
} else if (document.getElementById) {
    document.onmousemove = captureMousePosition;
}
function captureMousePosition(e) {
    if (document.layers) {
        yMousePos = e.pageY;
    } else if (document.all) {
        yMousePos = window.event.y;
    } else if (document.getElementById) {
        yMousePos =  e.pageY;
    }
}