//.. questo va dopo head
//.. <script language="javaScript" src="dateformat.js"></script>	
//..questo va su tag html della data
//.. onKeyUp="DateFormat(this,this.value,event,false);return false;" 
//.. onBlur="DateFormat(this,this.value,event,true);return false;"
//..


var isNav4 = false, isNav5 = false, isIE4 = false
var strSeperator = "/"; 
// la prossima variabile setta il formato data da utilizzare
// 1 = mm/dd/yyyy
// 2 = yyyy/mm/dd
// 3 = dd/mm/yyyy
var vDateType = 3; 
var vYearType = 4; //Set to 2 or 4 for number of digits in the year for Netscape
var err = 0; // Set the error code to a default of zero
if(navigator.appName == "Netscape") {
	if (navigator.appVersion < "5") {
	isNav4 = true;
	isNav5 = false;
}
else
	if (navigator.appVersion > "4") {
		isNav4 = false;
		isNav5 = true;
	}
}
else {
	isIE4 = true;
}
function DateFormat(vDateName, vDateValue, e, dateCheck) {
//Inserisci una tilde ~ come primo numero e visualizzi le variabili d'ambiente
if (vDateValue == "~") {
	alert("AppVersion = "+navigator.appVersion+" \nNav. 4 Version = "+isNav4+" \nNav. 5 Version = "+isNav5+" \nIE Version = "+isIE4+" \nYear Type = "+vYearType+" \nDate Type = "+vDateType+" \nSeparator = "+strSeperator);
	vDateName.value = "";
	vDateName.focus();
return true;
}
var whichCode = (window.Event) ? e.which : e.keyCode;
// il dateCheck lavorerà solamente se l'anno è all'ultima posizione ex.. mm/dd/yyyy format
// Il prossimo comando setterà dateCheck a falso se non fosse = 3.
if (vDateType != 3)
	dateCheck = false;
//Elimina tutti i codici ASCII non validi
var alphaCheck = " abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
if (alphaCheck.indexOf(vDateValue) >= 1) {
	if (isNav4) {
		vDateName.value = "";
		vDateName.focus();
		vDateName.select();
		return false;
	}
	else {
		vDateName.value = vDateName.value.substr(0, (vDateValue.length-1));
		return false;
	} 
}
if (whichCode == 8) //Ignore the Netscape value for backspace. IE has no value
	return false;
else {
	//Crea stringhe numerich per i valori 0123456789/
	var strCheck = '47,48,49,50,51,52,53,54,55,56,57,58,59,95,96,97,98,99,100,101,102,103,104,105';
if (strCheck.indexOf(whichCode) != -1) {
	if (isNav4) {
		if (((vDateValue.length < 6 && dateCheck) || (vDateValue.length == 7 && dateCheck)) && (vDateValue.length >=1)) {
			alert("Data non valida\nReinserirla per favore.");
			vDateName.value = "";
			vDateName.focus();
			vDateName.select();
			return false;
		}
		if (vDateValue.length == 6 && dateCheck) {
			var mDay = vDateName.value.substr(2,2);
			var mMonth = vDateName.value.substr(0,2);
			var mYear = vDateName.value.substr(4,4)
			//Cambia la digitazione degli anni da due a quattro
		if (mYear.length == 2 && vYearType == 4) {
			var mToday = new Date();
			//Se l'anno è più grande di 30 pone Anno a 1900 altrimenti a 2000
			var checkYear = mToday.getFullYear() + 30; 
			var mCheckYear = '20' + mYear;
		if (mCheckYear >= checkYear)
			mYear = '19' + mYear;
		else
			mYear = '20' + mYear;
}
vDateName.value = mMonth+strSeperator+mDay+strSeperator+mYear;
	if (!dateValid(vDateName)) {
		alert("Data non valida\nReinserirla per favore.");
		vDateName.value = "";
		vDateName.focus();
		vDateName.select();
		return false;
	}
return true;
}
else {
	if (vDateValue.length == 8  && dateCheck) {
		if (vDateType == 1) {
			var mDay = vDateName.value.substr(2,2);
			var mMonth = vDateName.value.substr(0,2);
			var mYear = vDateName.value.substr(4,4)
			vDateName.value = mMonth+strSeperator+mDay+strSeperator+mYear;
}
	if (vDateType == 2) {
		var mYear = vDateName.value.substr(0,4)
		var mMonth = vDateName.value.substr(6,2);
		var mDay = vDateName.value.substr(8,2);	
		vDateName.value = mYear+strSeperator+mMonth+strSeperator+mDay;
}
	if (vDateType == 3) {
	var mYear = vDateName.value.substr(0,4)
	var mMonth = vDateName.value.substr(6,2);
	var mDay = vDateName.value.substr(8,2);
	vDateName.value =mDay +strSeperator+mMonth+strSeperator+mYear;
	}
}               
if (vDateValue.length >= 8  && dateCheck) {
		if (!dateValid(vDateName)) {
			alert("Data non valida\nReinserirla per favore.");
			vDateName.value = "";
			vDateName.focus();
			vDateName.select();
			return false;
			}
		}
	}
}
else {
	if (((vDateValue.length < 8 && dateCheck) || (vDateValue.length == 9 && dateCheck)) && (vDateValue.length >=1)) {
		alert("Data non valida\nReinserirla per favore.");
		vDateName.value = "";
		vDateName.focus();
		return true;
	}
if (vDateValue.length == 8 && dateCheck) {
		if (vDateValue.length == 8 && dateCheck) {
			var mMonth = vDateName.value.substr(0,2);
			var mDay = vDateName.value.substr(3,2);
			var mYear = vDateName.value.substr(6,4)
			//Cambia la digitazione degli anni da due a quattro
if (mYear.length == 2 && vYearType == 4) {
			var mToday = new Date();
			//Cambia l'anno da 1900 a 2000 se la digitazione è superiore a 30
			var checkYear = mToday.getFullYear() + 30; 
			var mCheckYear = '20' + mYear;
if (mCheckYear >= checkYear)
	mYear = '19' + mYear;
	else
	mYear = '20' + mYear;
	}
	vDateName.value = mMonth+strSeperator+mDay+strSeperator+mYear;
} 
if (!dateValid(vDateName)) {
	alert("Data non valida\nReinserirla per favore.");
	vDateName.value = "";
	vDateName.focus();
	return true;
}
return true;
}
else {
	if (vDateType == 1) {
		if (vDateValue.length == 2) {
		vDateName.value = vDateValue+strSeperator;
		}
		if (vDateValue.length == 5) {
		vDateName.value = vDateValue+strSeperator;
		}
	}
	if (vDateType == 2) {
		if (vDateValue.length == 4) {
		vDateName.value = vDateValue+strSeperator;
		}
		if (vDateValue.length == 7) {
		vDateName.value = vDateValue+strSeperator;
		}
	}
	if (vDateType == 3){
	if (vDateValue.length == 2) {
		vDateName.value = vDateValue+strSeperator;
		}
		if (vDateValue.length == 5) {
		vDateName.value = vDateValue+strSeperator;
		}
	
	} 
}
}
if (vDateValue.length == 10   && dateCheck) {
	if (!dateValid(vDateName)) {
		alert("Data non valida\nReinserirla per favore.");
		vDateName.focus();
		vDateName.select();
	}
}
return false;
}
else {
// Se il valore non è nel ritorno stringa la stringa diminuisce l'ultima digitazione
	if (isNav4) {
		vDateName.value = "";
		vDateName.focus();
		vDateName.select();
		return false;
	}
else {
	vDateName.value = vDateName.value.substr(0, (vDateValue.length-1));
	return false;
		}
	}
	}
}
function dateValid(objName) {
var strDate;
var strDateArray;
var strDay;
var strMonth;
var strYear;
var intday;
var intMonth;
var intYear;
var booFound = false;
var datefield = objName;
var strSeparatorArray = new Array("-"," ","/",".");
var intElementNr;
// var err = 0;
var strMonthArray = new Array(12);
strMonthArray[0] = "Jan";
strMonthArray[1] = "Feb";
strMonthArray[2] = "Mar";
strMonthArray[3] = "Apr";
strMonthArray[4] = "May";
strMonthArray[5] = "Jun";
strMonthArray[6] = "Jul";
strMonthArray[7] = "Aug";
strMonthArray[8] = "Sep";
strMonthArray[9] = "Oct";
strMonthArray[10] = "Nov";
strMonthArray[11] = "Dec";
strDate = datefield.value;
if (strDate.length < 1) {
	return true;
}
for (intElementNr = 0; intElementNr < strSeparatorArray.length; intElementNr++) {
	if (strDate.indexOf(strSeparatorArray[intElementNr]) != -1) {
		strDateArray = strDate.split(strSeparatorArray[intElementNr]);
		if (strDateArray.length != 3) {
			err = 1;
		return false;
	}
	else {
		if (vDateType == 1) {
			strDay = strDateArray[0];
			strMonth = strDateArray[1];
			strYear = strDateArray[2];
		}
		if (vDateType == 2) {
			strYear = strDateArray[0];
			strMonth = strDateArray[1];
			strDay = strDateArray[2];
		}
		if (vDateType == 3) {
			strMonth = strDateArray[0];
			strDay = strDateArray[1];
			strYear = strDateArray[2];
		}
	
}
booFound = true;
}
}
if (booFound == false) {
if (strDate.length>5) {
	if (vDateType == 1) {
		strDay = strDate.substr(0, 2);
		strMonth = strDate.substr(2, 2);
		strYear = strDate.substr(4);
	}
	if (vDateType == 2) {
		strYear = strDate.substr(0,4);
		strDay = strDate.substr(8, 2);
		strMonth = strDate.substr(6, 2);
	}
	if (vDateType == 3) {
		strDay = strDate.substr(0, 2);
		strMonth = strDate.substr(2, 2);
		strYear = strDate.substr(4);
	}
}
}
//aggiusta l'immisione degli anni a due cifre
if (strYear.length == 2) {
strYear = '20' + strYear;
}
if (vDateType == 1) {
	strTemp = strDay;
	strDay = strMonth;
	strMonth = strTemp;
}
if (vDateType == 3) {
	strTemp = strDay;
	strDay = strMonth;
	strMonth = strTemp;
}
/*if (vDateType == 3){
	strTemp = strMonth;
	strMonth = strDay;
	strDay = strTemp;
	}
*/
intday = parseInt(strDay, 10);
if (isNaN(intday)) {
err = 2;
return false;
}
intMonth = parseInt(strMonth, 10);
if (isNaN(intMonth)) {
for (i = 0;i<12;i++) {
if (strMonth.toUpperCase() == strMonthArray[i].toUpperCase()) {
intMonth = i+1;
strMonth = strMonthArray[i];
i = 12;
}
}
if (isNaN(intMonth)) {
err = 3;
return false;
}
}
intYear = parseInt(strYear, 10);
if (isNaN(intYear)) {
err = 4;
return false;
}
if (intMonth > 12 || intMonth < 1) {
err = 5;
return false;
}
if ((intMonth == 1 || intMonth == 3 || intMonth == 5 || intMonth == 7 || intMonth == 8 || intMonth == 10 || intMonth == 12) && (intday > 31 || intday < 1)) {
err = 6;
return false;
}
if ((intMonth == 4 || intMonth == 6 || intMonth == 9 || intMonth == 11) && (intday > 30 || intday < 1)) {
err = 7;
return false;
}
if (intMonth == 2) {
if (intday < 1) {
err = 8;
return false;
}
if (LeapYear(intYear) == true) {
if (intday > 29) {
err = 9;
return false;
}
}
else {
if (intday > 28) {
err = 10;
return false;
}
}
}
return true;
}
function LeapYear(intYear) {
if (intYear % 100 == 0) {
if (intYear % 400 == 0) { return true; }
}
else {
if ((intYear % 4) == 0) { return true; }
}
return false;
}