function resizeText(multiplier) {
  if (document.body.style.fontSize == "") {
    document.body.style.fontSize = "1.0em";
  }
  document.body.style.fontSize = parseFloat(document.body.style.fontSize) + (multiplier * 0.2) + "em";
}
<!--
function entra(){
	window.open('https://www.isideonline.it/relaxbanking/sso.Login','frmLogin','toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=no,width=265,height=280,top=5,left=5');
}
function Popup(url)  
{
 var width  = 350;
 var height = 500;
 var left   = (screen.width  - width)/2;
 var top    = (screen.height - height)/2;
 var params = 'width='+width+', height='+height;
 params += ', top='+top+', left='+left;
 params += ', directories=no';
 params += ', location=no';
 params += ', menubar=no';
 params += ', resizable=no';
 params += ', scrollbars=no';
 params += ', status=no';
 params += ', toolbar=no';
 
//alert(params);
//alert(url);
window.open(url,'Titolo', params);
//window.open("a.html","titolo","toolbar=no");
 
} 
 
function inviaPagina(urlAltro){
		//alert(urlAltro);
		apriFinestra (500, 550, "inviaPagina", "/Pagine/toolbox/SendMail.aspx", urlAltro)
	}
function apriFinestra (x, y, nome, url,urlAltro) { 
url = url+"?PageURL="+urlAltro;
//alert("x:"+x+"-y:"+y+"-nome:"+nome+"-url:"+url);
	nome = nome.toUpperCase() 
	if(x > (screen.width - 100)) 
		x = (screen.width - 150) 
	if(y > (screen.height - 100)) 
		y = (screen.height - 150) 
	var w = x 
	var h = y 
	var l,t; 
	l = Math.round((screen.width / 2) - (w / 2)); 
	t = Math.round((screen.height / 2) - (h / 2)) - 10; 
	eval("WIN_" + nome + " = window.open(url,nome,\"resizable=yes,scrollbars=yes,width=\"+w+\",height=\"+h+\",left=\"+ l +\",top=\"+ t);") 
	try { 
		eval("WIN_" + nome + ".focus()") 
	} catch(err) { 
		setTimeout("WIN_" + nome + ".focus()", 2000) 
	} 
}

	function display (id)
{
	x=document.getElementById(id);
	if (x.style.display=='none')
	{
		x.style.display=''
	}else
	{
		x.style.display='none'
	}
}
//-->