function createCookie(name,value,days) {
  if (days) {
    var date = new Date();
    date.setTime(date.getTime()+(days*24*60*60*1000));
    var expires = '; expires='+date.toGMTString();
  }
  else expires = '';
  document.cookie = name+'='+value+expires+'; path=/';
}

function readCookie(name) {
  var nameEQ = name + '=';
  var ca = document.cookie.split(';');
  for(var i=0;i < ca.length;i++) {
    var c = ca[i];
    while (c.charAt(0)==' ') c = c.substring(1,c.length);
    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
  }
  return null;
}

function setFontSize(size) {
	var body = document.getElementsByTagName('body')[0];
	var percentuale = "70%"; // default
	if (size == 1) percentuale = "80%";
	if (size == 2) percentuale = "100%";
	if (size == 3) percentuale = "110%";
	if (size == 4) percentuale = "120%";
	if (size == 5) percentuale = "130%";
	body.style.fontSize = percentuale;
	createCookie('TuoSitoFontSize',size,365);
}


function upDownFontSize(up_down){
	var size = readCookie('TuoSitoFontSize');
//sostituito controllo	size== null con isNaN(size)
	if (isNaN(size)){
		var body = document.getElementsByTagName('body')[0];
		var percentuale=body.style.fontSize;
		if (percentuale=="80%") size=1;
		if (percentuale=="100%") size=2;
		if (percentuale=="110%") size=3;
		if (percentuale=="120%") size=4;
		if (percentuale=="130%") size=5;
	}
	if ((up_down=="+") && (size!=5)){
		size=parseInt(size)+1;
	}
	if ((up_down=="-") && (size!=1)){
		size=parseInt(size)-1;
	}
	if (up_down=="="){
		size=2;
	}
	setFontSize(size);/**/
}

window.onload = function() {
	var size = readCookie('TuoSitoFontSize');
	setFontSize(size);
}