// serve per switchare tra display block e none 
// ossia visualizzaree o nascondere l'oggetto div 'obj'
// passato come variabile
function showhide(obj)
{
  if (document.getElementById(obj).style.display=='block') {
		// fai .....
	document.getElementById(obj).style.display='none';		
  } else {
		// fai .....
	document.getElementById(obj).style.display='block';		
  }
}

<!-- finestra popup generica con variabili centrata -->
function popup_generica (url,wname,w,h,scroll,browserloc,menubar,resizable,status,directories,toolbar) {
	var winl = (screen.width - w) / 2 - 5;
	var wint = (screen.height - h) / 2 -80;
	finestra = window.open(url,wname,'top='+wint+',left='+winl+',width='+w+',height='+h+',buttons=1,scrollbars='+scroll+',location='+browserloc+',menubar='+menubar+',resizable='+resizable+',status='+status+',directories='+directories+',toolbar='+toolbar+',copyhistory=Yes');
}

<!-- script per aggiugnere ai preferiti-->
function addBookmark(title,url) {
  if (window.sidebar)
  {
    window.sidebar.addPanel(title, url,"");
  }
  else if( document.all )
  {
    window.external.AddFavorite( url, title);
  }
  else
  {
    return true;
  }
}

function toggleContent(name,n) {
	var i,t='',el = document.getElementById(name);
	if (!el.origCont) el.origCont = el.innerHTML;
	
	for (i=0;i<n;i++) t += el.origCont;
	el.innerHTML = t;
	}



// funzione per contare/limitare il nr di caratteri massimi da immettere

function wordCounter(field, countfield, maxlimit) {
wordcounter=0;
for (x=0;x<field.value.length;x++) {
      if (field.value.charAt(x) == " " && field.value.charAt(x-1) != " ")  {wordcounter++}  
	  if (wordcounter > maxlimit) {field.value = field.value.substring(0, x);}
      else {countfield.value = maxlimit - wordcounter;}
      }
   }

function textCounter(field, countfield, maxlimit) {
  if (field.value.length > maxlimit)
      {field.value = field.value.substring(0, maxlimit);}
      else
      {countfield.value = maxlimit - field.value.length;}
  }
  
  // verifica per campi modulo checkbox e radio button in combinazione con checkfields
function WithoutCheck(ss) {
	if(ss.checked) { return false; }
	return true;
}

function NoneWithCheck(ss) {
	for(var i = 0; i < ss.length; i++) {
		if(ss[i].checked) { return false; }
		}
return true;
}