function send(formName) {
	prosegui = false;
	if (formName!='') {
		form = eval("document."+formName)
		if (form) {
			prosegui = true;
			for (i=0;i<form.elements.length;i++) {
				ID = form.elements[i].id;
				if ((ID.substr(0,1) == "M")&&(isEmpty(form.elements[i]))) {
					alert("Compilare tutti i campi obbligatori: \'"+ID.substr(4)+"\'");
					form.elements[i].focus();
					prosegui = false;
					break;
				}
				switch (ID.substr(1,3)) {
					case "eF_":
						if (!(ctrlEmail(form.elements[i]))) {
							alert("Inserire un indirizzo e-mail valido nel campo \'"+ID.substr(4)+"\'");
							form.elements[i].focus();
							prosegui = false;
						}
						break;
					case "uF_":
						if (!(isWWW(form.elements[i]))) {
							alert("Inserire un indirizzo web valido nel campo \'"+ID.substr(4)+"\'");
							form.elements[i].focus();
							prosegui = false;
						}
						break;
					case "pF_":
						if (form.elements[i].value!=form.password2.value) {
							alert("La password e la password di controllo non coincidono, controllare il campo \'"+ID.substr(4)+"\'");
							form.elements[i].focus();
							prosegui = false;
						}
						break;
					case "nF_":
						if (!(isNumber(form.elements[i]))) {
							alert("Inserire un numero valido nel campo \'"+ID.substr(4)+"\'");
							form.elements[i].focus();
							prosegui = false;
						}
						break;
					case "iF_":
						if (!(isNumberInt(form.elements[i]))) {
							alert("Inserire un numero intero valido nel campo \'"+ID.substr(4)+"\'");
							form.elements[i].focus();
							prosegui = false;
						}
						break;
					case "fN_":
						if (!(isFloatNumber(form.elements[i]))) {
							alert("Inserire un numero valido nel campo \'"+ID.substr(4)+"\'");
							form.elements[i].focus();
							prosegui = false;
						}
						break;
					case "sS_":
						if (!(isRightString(form.elements[i].value))) {
							alert("Sono accettati solo caratteri alfanumerici nel campo \'"+ID.substr(4)+"\'");
							form.elements[i].focus();
							prosegui = false;
						}
						break;
					case "sO_":
						if (isEmpty(form.elements[i].selectIndex)) {
							alert("Scegliere una voce per il menu a tendina \'"+ID.substr(4)+"\'");
							form.elements[i].focus();
							prosegui = false;
						}
						break;
				}
				if (!prosegui) {
					return false
					break;
				}
			}
//			if (prosegui) form.submit();
		}
	}
	return prosegui;
}

function controllodate(laform){
	//imposto la variabile sbagliato come false di predefinito, se trovo un errore questa diventa true
	var sbagliato=false;
	//recupero i valori delle date
	j=laform.dalg.selectedIndex;
	dalg=laform.dalg.options[j].value;
	j=laform.dalm.selectedIndex;
	dalm=laform.dalm.options[j].value;
	j=laform.dala.selectedIndex;
	dala=laform.dala.options[j].value;

	j=laform.alg.selectedIndex;
	alg=laform.alg.options[j].value;
	j=laform.alm.selectedIndex;
	alm=laform.alm.options[j].value;
	j=laform.ala.selectedIndex;
	ala=laform.ala.options[j].value;
	//window.alert (dalg+"/"+dalm+"/"+dala+"-------"+alg+"/"+alm+"/"+ala); 
	if (dalg==alg && dalm==alm && dala==ala){
	window.alert("Data di partenza e data di arrivo uguali!\nControlla bene i tuoi dati");
	sbagliato=true;
	}
	if (dalg==31 && (dalm==4 || dalm==6 || dalm==9 || dalm==11)){
	window.alert("Data di partenza non valida!");
	sbagliato=true;
	}
	if (dalm==2){
		if (dalg>29){
			window.alert("Data di partenza non valida!");
			sbagliato=true;
		}else{
			if (dalg==29){
				if (!(dala % 4 == 0 && dala % 100 != 0 || dala % 400 == 0 )){
					window.alert("Non è un anno BISESTILE \n Febbraio ha solo 28 giorni");
					sbagliato=true;
				}
			}
		}
	}
	if (alg==31 && (alm==4 || alm==6 || alm==9 || alm==11)){
	window.alert("Data di arrivo non valida!");
	sbagliato=true;
	}
	if (alm==2){
		if (alg>29){
			window.alert("Data di arrivo non valida!");
			sbagliato=true;
		}else{
			if (alg==29){
				if (!(ala % 4 == 0 && ala % 100 != 0 || ala % 400 == 0 )){
					window.alert("Non è un anno BISESTILE  \n Febbraio ha solo 28 giorni");
					sbagliato=true;
				}
			}
		}
	}
	if (!sbagliato){
		var d1=new Date(dala,dalm,dalg);
		var d2=new Date(ala,alm,alg);
		if (d1>d2){
			window.alert("Data di partenza maggiore della data di arrivo!");
			sbagliato = true
		}
	}
	return !sbagliato
}

<!-- Original:  Simon Tneoh (tneohcb@pc.jaring.my) -->

<!-- This script and many more are available free online at -->
<!-- The JavaScript Source!! http://javascript.internet.com -->

<!-- Begin
var Cards = new makeArray(8);
Cards[0] = new CardType("MasterCard", "51,52,53,54,55", "16");
var MasterCard = Cards[0];
Cards[1] = new CardType("VisaCard", "4", "13,16");
var VisaCard = Cards[1];
Cards[2] = new CardType("AmExCard", "34,37", "15");
var AmExCard = Cards[2];
Cards[3] = new CardType("DinersClubCard", "30,36,38", "14");
var DinersClubCard = Cards[3];
Cards[4] = new CardType("DiscoverCard", "6011", "16");
var DiscoverCard = Cards[4];
Cards[5] = new CardType("enRouteCard", "2014,2149", "15");
var enRouteCard = Cards[5];
Cards[6] = new CardType("JCBCard", "3088,3096,3112,3158,3337,3528", "16");
var JCBCard = Cards[6];
var LuhnCheckSum = Cards[7] = new CardType();
var letter = /^[a-zA-Z\s]+$/;

/*************************************************************************\
CheckCardNumber(form)
function called when users click the "check" button.
\*************************************************************************/

function CheckCardNumber(form) {
	var tmpyear;
	if (!letter.test(form.CCName.value)){
			alert("The name as it appears on the credit card is required.");
			form.CCName.focus();
		return false;
	}
	if (form.CardNumber.value.length == 0) {
		alert("Please enter a Card Number.");
		form.CardNumber.focus();
		return false;
	}
	if (form.ExpYear.value.length == 0) {
		alert("Please enter the Expiration Year.");
		form.ExpYear.focus();
		return false;
	}
//	if (form.ExpYear.value > 96)
//		tmpyear = "19" + form.ExpYear.value;
//	else if (form.ExpYear.value < 21)
//		tmpyear = "20" + form.ExpYear.value;
//	else {
//		alert("The Expiration Year is not valid.");
//		return false;
//	}
	if (form.ExpYear.value > 1996 && form.ExpYear.value < 2021)
		tmpyear = form.ExpYear.value 
	else {
		alert("The Expiration Year is not valid.");
		return false;
	}
	tmpmonth = form.ExpMon.options[form.ExpMon.selectedIndex].value;
	// The following line doesn't work in IE3, you need to change it
	// to something like "(new CardType())...".
	// if (!CardType().isExpiryDate(tmpyear, tmpmonth)) {
	if (!(new CardType()).isExpiryDate(tmpyear, tmpmonth)) {
		alert("This card has already expired.");
		return;
	}
	card = form.CardType.options[form.CardType.selectedIndex].value;
	var retval = eval(card + ".checkCardNumber(\"" + form.CardNumber.value +
	"\", " + tmpyear + ", " + tmpmonth + ");");
	cardname = "";
	if (retval)
		
		// comment this out if used on an order form
		//alert("This card number appears to be valid.");
		return true
	else {
		// The cardnumber has the valid luhn checksum, but we want to know which
		// cardtype it belongs to.
		for (var n = 0; n < Cards.size; n++) {
			if (Cards[n].checkCardNumber(form.CardNumber.value, tmpyear, tmpmonth)) {
				cardname = Cards[n].getCardType();
				break;
			}
		}
		if (cardname.length > 0) {
			alert("This looks like a " + cardname + " number, not a " + card + " number.");
		}
		else {
			alert("This card number is not valid.");
		}
		return false
	}
}
/*************************************************************************\
Object CardType([String cardtype, String rules, String len, int year, 
                                        int month])
cardtype    : type of card, eg: MasterCard, Visa, etc.
rules       : rules of the cardnumber, eg: "4", "6011", "34,37".
len         : valid length of cardnumber, eg: "16,19", "13,16".
year        : year of expiry date.
month       : month of expiry date.
eg:
var VisaCard = new CardType("Visa", "4", "16");
var AmExCard = new CardType("AmEx", "34,37", "15");
\*************************************************************************/
function CardType() {
	var n;
	var argv = CardType.arguments;
	var argc = CardType.arguments.length;

	this.objname = "object CardType";

	var tmpcardtype = (argc > 0) ? argv[0] : "CardObject";
	var tmprules = (argc > 1) ? argv[1] : "0,1,2,3,4,5,6,7,8,9";
	var tmplen = (argc > 2) ? argv[2] : "13,14,15,16,19";

	this.setCardNumber = setCardNumber;  // set CardNumber method.
	this.setCardType = setCardType;  // setCardType method.
	this.setLen = setLen;  // setLen method.
	this.setRules = setRules;  // setRules method.
	this.setExpiryDate = setExpiryDate;  // setExpiryDate method.

	this.setCardType(tmpcardtype);
	this.setLen(tmplen);
	this.setRules(tmprules);
	if (argc > 4)
		this.setExpiryDate(argv[3], argv[4]);

	this.checkCardNumber = checkCardNumber;  // checkCardNumber method.
	this.getExpiryDate = getExpiryDate;  // getExpiryDate method.
	this.getCardType = getCardType;  // getCardType method.
	this.isCardNumber = isCardNumber;  // isCardNumber method.
	this.isExpiryDate = isExpiryDate;  // isExpiryDate method.
	this.luhnCheck = luhnCheck;// luhnCheck method.
	return this;
}

/*************************************************************************\
boolean checkCardNumber([String cardnumber, int year, int month])
return true if cardnumber pass the luhncheck and the expiry date is
valid, else return false.
\*************************************************************************/
function checkCardNumber() {
	var argv = checkCardNumber.arguments;
	var argc = checkCardNumber.arguments.length;
	var cardnumber = (argc > 0) ? argv[0] : this.cardnumber;
	var year = (argc > 1) ? argv[1] : this.year;
	var month = (argc > 2) ? argv[2] : this.month;

	this.setCardNumber(cardnumber);
	this.setExpiryDate(year, month);

	if (!this.isCardNumber())
		return false;
	if (!this.isExpiryDate())
		return false;

	return true;
}
/*************************************************************************\
String getCardType()
return the cardtype.
\*************************************************************************/
function getCardType() {
	return this.cardtype;
}
/*************************************************************************\
String getExpiryDate()
return the expiry date.
\*************************************************************************/
function getExpiryDate() {
	return this.month + "/" + this.year;
}
/*************************************************************************\
boolean isCardNumber([String cardnumber])
return true if cardnumber pass the luhncheck and the rules, else return
false.
\*************************************************************************/
function isCardNumber() {
	var argv = isCardNumber.arguments;
	var argc = isCardNumber.arguments.length;
	var cardnumber = (argc > 0) ? argv[0] : this.cardnumber;
	if (!this.luhnCheck())
		return false;

	for (var n = 0; n < this.len.size; n++)
		if (cardnumber.toString().length == this.len[n]) {
			for (var m = 0; m < this.rules.size; m++) {
				var headdigit = cardnumber.substring(0, this.rules[m].toString().length);
				if (headdigit == this.rules[m])
					return true;
			}
			return false;
		}
	return false;
}

/*************************************************************************\
boolean isExpiryDate([int year, int month])
return true if the date is a valid expiry date,
else return false.
\*************************************************************************/
function isExpiryDate() {
	var argv = isExpiryDate.arguments;
	var argc = isExpiryDate.arguments.length;

	year = argc > 0 ? argv[0] : this.year;
	month = argc > 1 ? argv[1] : this.month;

	if (!isNum(year+""))
		return false;
	if (!isNum(month+""))
		return false;
	today = new Date();
	expiry = new Date(year, month);
	if (today.getTime() > expiry.getTime())
		return false;
	else
		return true;
}

/*************************************************************************\
boolean isNum(String argvalue)
return true if argvalue contains only numeric characters,
else return false.
\*************************************************************************/
function isNum(argvalue) {
	argvalue = argvalue.toString();

	if (argvalue.length == 0)
		return false;

	for (var n = 0; n < argvalue.length; n++)
		if (argvalue.substring(n, n+1) < "0" || argvalue.substring(n, n+1) > "9")
			return false;

	return true;
}

/*************************************************************************\
boolean luhnCheck([String CardNumber])
return true if CardNumber pass the luhn check else return false.
Reference: http://www.ling.nwu.edu/~sburke/pub/luhn_lib.pl
\*************************************************************************/
function luhnCheck() {
	var argv = luhnCheck.arguments;
	var argc = luhnCheck.arguments.length;

	var CardNumber = argc > 0 ? argv[0] : this.cardnumber;

	if (! isNum(CardNumber)) {
		return false;
	  }

	var no_digit = CardNumber.length;
	var oddoeven = no_digit & 1;
	var sum = 0;

	for (var count = 0; count < no_digit; count++) {
		var digit = parseInt(CardNumber.charAt(count));
		if (!((count & 1) ^ oddoeven)) {
			digit *= 2;
			if (digit > 9)
				digit -= 9;
		}
		sum += digit;
	}
	if (sum % 10 == 0)
		return true;
	else
		return false;
}

/*************************************************************************\
ArrayObject makeArray(int size)
return the array object in the size specified.
\*************************************************************************/
function makeArray(size) {
	this.size = size;
	return this;
}

/*************************************************************************\
CardType setCardNumber(cardnumber)
return the CardType object.
\*************************************************************************/
function setCardNumber(cardnumber) {
	this.cardnumber = cardnumber;
	return this;
}

/*************************************************************************\
CardType setCardType(cardtype)
return the CardType object.
\*************************************************************************/
function setCardType(cardtype) {
	this.cardtype = cardtype;
	return this;
}

/*************************************************************************\
CardType setExpiryDate(year, month)
return the CardType object.
\*************************************************************************/
function setExpiryDate(year, month) {
	this.year = year;
	this.month = month;
	return this;
}

/*************************************************************************\
CardType setLen(len)
return the CardType object.
\*************************************************************************/
function setLen(len) {
	// Create the len array.
	if (len.length == 0 || len == null)
		len = "13,14,15,16,19";

	var tmplen = len;
	n = 1;
	while (tmplen.indexOf(",") != -1) {
		tmplen = tmplen.substring(tmplen.indexOf(",") + 1, tmplen.length);
		n++;
	}
	this.len = new makeArray(n);
	n = 0;
	while (len.indexOf(",") != -1) {
		var tmpstr = len.substring(0, len.indexOf(","));
		this.len[n] = tmpstr;
		len = len.substring(len.indexOf(",") + 1, len.length);
		n++;
	}
	this.len[n] = len;
	return this;
}

/*************************************************************************\
CardType setRules()
return the CardType object.
\*************************************************************************/
function setRules(rules) {
	// Create the rules array.
	if (rules.length == 0 || rules == null)
		rules = "0,1,2,3,4,5,6,7,8,9";
	  
	var tmprules = rules;
	n = 1;
	while (tmprules.indexOf(",") != -1) {
		tmprules = tmprules.substring(tmprules.indexOf(",") + 1, tmprules.length);
		n++;
	}
	this.rules = new makeArray(n);
	n = 0;
	while (rules.indexOf(",") != -1) {
		var tmpstr = rules.substring(0, rules.indexOf(","));
		this.rules[n] = tmpstr;
		rules = rules.substring(rules.indexOf(",") + 1, rules.length);
		n++;
	}
	this.rules[n] = rules;
	return this;
}
//  End -->