function checkMail(dati) {
    if ((dati.indexOf("@") == -1) |
		(dati.indexOf(".") == -1) |
		(dati.length < 7)) {
			alert(dati+" non è una e-mail valida");
			return (false);
		}
 return (true);
}

function checkChars(data, type)
{
switch (type) {
case 0:
 var checkOK = "0123456789";  // only numbers 
 break;
case 1:
 var checkOK = "0123456789-/"; // dates - tel num
 break;
case 2:
 var checkOK = "0123456789."; // float numbers or IP address
 break;
case 3:
 var checkOK = "0123456789:"; // time
 break;
case 4:
 var checkOK = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz+- /%"; // alphanum
 break;
case 5:		   // p.iva
 if (data.length != 11)
 {
  return (false);
 }
 var checkOK = "0123456789";
 break;
case 6: 
 return(true);
 break;
}

for (var i=0; i<data.length; i++) {
 if (checkOK.indexOf(data.charAt(i)) == -1)
  return (false);
}
return (true);
}

function Validate(objt, type, canempty)
{
if (objt.value != "")
{
 if (!checkChars(objt.value, type))
 {
	 alert("errore in "+objt.name);
//	 objt.value = "";
	 objt.focus();
	 return (false);
 }
 return(true);
}
else if (canempty)
 return (true);
else
 {
	 alert(objt.name+" è obbligatorio");
	 objt.focus();
	 return (false);
 } 
}