// VARIABLE DECLARATIONS
var digits = "0123456789";

// whitespace characters
var whitespace = " \t\n\r";

// decimal point character differs by language and culture
var decimalPointDelimiter = "."

// non-digit characters which are allowed in phone numbers
var phoneNumberDelimiters = "/- ";

// characters which are allowed in US phone numbers
var validUSPhoneChars = digits + phoneNumberDelimiters;


// CONSTANT STRING DECLARATIONS

// m is an abbreviation for "missing"
var mPrefix = "Non hai inserito il valore nel campo ";
var mSuffix = ". Questo è un campo richiesto. Inserirlo ora.";

// s is an abbreviation for "string"
var sCognome = "Cognome";
var sNome = "Nome";

// i is an abbreviation for "invalid"
var iPrefix = "Il valore inserito nel campo ";
var iSuffix = " non è valido. Reinserirlo ora.";

var iUSPhone = "Inserire un numero telefonico valido (es: 081 123 4567). Reinserire il campo.";
var iEmail = "Inserire un indirizzo email valido (es: nome@dominio.it). Reinserire il campo.";
var iName = "Inserire un nome valido. Reinserire il campo.";
var iUser = "Username o Password non consentita. Reinserire il campo.";
var iPwd = "Password errata...! Reinserire il campo.";
var iDay = "This field must be a day number between 1 and 31.  Please reenter it now.";
var iMonth = "This field must be a month number between 1 and 12.  Please reenter it now.";
var iYear = "This field must be a 2 or 4 digit year number.  Please reenter it now.";
var iDatePrefix = "The Day, Month, and Year for ";
var iDateSuffix = " do not form a valid date.  Please reenter them now.";

// p is an abbreviation for "prompt"
var pEntryPrompt = "Inserire ";
var pPhone = "numero (es: 081 123 4567).";
var pEmail = "indirizzo email (es: nome@dominio.it).";
var pDay = "day number between 1 and 31.";
var pMonth = "month number between 1 and 12.";
var pYear = "2 or 4 digit year number.";


var defaultEmptyOK = false;

function makeArray(n) {
//*** BUG: If I put this line in, I get two error messages:
//(1) Window.length can't be set by assignment
//(2) daysInMonth has no property indexed by 4
//If I leave it out, the code works fine.
//   this.length = n;
   for (var i = 1; i <= n; i++) {
      this[i] = 0
   }
   return this
}

var daysInMonth = makeArray(12);
daysInMonth[1] = 31;
daysInMonth[2] = 29;   // must programmatically check this
daysInMonth[3] = 31;
daysInMonth[4] = 30;
daysInMonth[5] = 31;
daysInMonth[6] = 30;
daysInMonth[7] = 31;
daysInMonth[8] = 31;
daysInMonth[9] = 30;
daysInMonth[10] = 31;
daysInMonth[11] = 30;
daysInMonth[12] = 31;


// Check whether string s is empty.
function isEmpty(s)
{   return ((s == null) || (s.length == 0))
}

// Returns true if string s is empty or
// whitespace characters only.
function isWhitespace (s)
{
	var i;
    // Is s empty?
    if (isEmpty(s)) return true;
    // Search through string's characters one by one
    // until we find a non-whitespace character.
    // When we do, return false; if we don't, return true.
    for (i = 0; i < s.length; i++)
    {
        // Check that current character isn't whitespace.
        var c = s.charAt(i);
        if (whitespace.indexOf(c) == -1) return false;
    }
    // All characters are whitespace.
    return true;
}

// Removes all characters which appear in string bag from string s.
function stripCharsInBag (s, bag)
{
	var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not in bag, append to returnString.
    for (i = 0; i < s.length; i++)
    {
        // Check that current character isn't whitespace.
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}

// Removes all characters which do NOT appear in string bag
// from string s.
function stripCharsNotInBag (s, bag)
{
	var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is in bag, append to returnString.
    for (i = 0; i < s.length; i++)
    {
        // Check that current character isn't whitespace.
        var c = s.charAt(i);
        if (bag.indexOf(c) != -1) returnString += c;
    }
    return returnString;
}

// Removes all whitespace characters from s.
// Global variable whitespace (see above)
// defines which characters are considered whitespace.
function stripWhitespace (s)
{   return stripCharsInBag (s, whitespace) }


// charInString (CHARACTER c, STRING s)
//
// Returns true if single character c (actually a string)
// is contained within string s.
function charInString (c, s)
{
	for (i = 0; i < s.length; i++)
    {   if (s.charAt(i) == c) return true;
    }
    return false
}

// Removes initial (leading) whitespace characters from s.
// Global variable whitespace (see above)
// defines which characters are considered whitespace.
function stripInitialWhitespace (s)
{
	var i = 0;
    while ((i < s.length) && charInString (s.charAt(i), whitespace))
       i++;
    return s.substring (i, s.length);
}


// Returns true if character c is an English letter
// (A .. Z, a..z).
function isLetter (c)
{   return ( ((c >= "a") && (c <= "z")) || ((c >= "A") && (c <= "Z")) ) }

// Returns true if character c is a digit
// (0 .. 9).
function isDigit (c)
{   return ((c >= "0") && (c <= "9")) }

// Returns true if character c is a letter or digit.
function isLetterOrDigit (c)
{   return (isLetter(c) || isDigit(c)) }



// isInteger (STRING s [, BOOLEAN emptyOK])
//
// Returns true if all characters in string s are numbers.
// EXAMPLE FUNCTION CALL:     RESULT:
// isInteger ("5")            true
// isInteger ("")             defaultEmptyOK
// isInteger ("-5")           false
// isInteger ("", true)       true
// isInteger ("", false)      false
// isInteger ("5", false)     true
function isInteger (s)
{
	var i;
    if (isEmpty(s))
       if (isInteger.arguments.length == 1) return defaultEmptyOK;
       else return (isInteger.arguments[1] == true);
    // Search through string's characters one by one
    // until we find a non-numeric character.
    // When we do, return false; if we don't, return true.
    for (i = 0; i < s.length; i++)
    {
        // Check that current character is number.
        var c = s.charAt(i);
        if (!isDigit(c)) return false;
    }
    // All characters are numbers.
    return true;
}

// isSignedInteger (STRING s [, BOOLEAN emptyOK])
//
// Returns true if all characters are numbers;
// first character is allowed to be + or - as well.
// EXAMPLE FUNCTION CALL:          RESULT:
// isSignedInteger ("5")           true
// isSignedInteger ("")            defaultEmptyOK
// isSignedInteger ("-5")          true
// isSignedInteger ("+5")          true
// isSignedInteger ("", false)     false
// isSignedInteger ("", true)      true
function isSignedInteger (s)
{
	if (isEmpty(s))
       if (isSignedInteger.arguments.length == 1) return defaultEmptyOK;
       else return (isSignedInteger.arguments[1] == true);
    else {
        var startPos = 0;
        var secondArg = defaultEmptyOK;
        if (isSignedInteger.arguments.length > 1)
            secondArg = isSignedInteger.arguments[1];
        // skip leading + or -
        if ( (s.charAt(0) == "-") || (s.charAt(0) == "+") )
           startPos = 1;
        return (isInteger(s.substring(startPos, s.length), secondArg))
    }
}

// isPositiveInteger (STRING s [, BOOLEAN emptyOK])
//
// Returns true if string s is an integer > 0.
function isPositiveInteger (s)
{   var secondArg = defaultEmptyOK;

    if (isPositiveInteger.arguments.length > 1)
        secondArg = isPositiveInteger.arguments[1];
    // The next line is a bit byzantine.  What it means is:
    // a) s must be a signed integer, AND
    // b) one of the following must be true:
    //    i)  s is empty and we are supposed to return true for
    //        empty strings
    //    ii) this is a positive, not negative, number
    return (isSignedInteger(s, secondArg)
         && ( (isEmpty(s) && secondArg)  || (parseInt (s) > 0) ) );
}

// isNonnegativeInteger (STRING s [, BOOLEAN emptyOK])
//
// Returns true if string s is an integer >= 0.
function isNonnegativeInteger (s)
{
	var secondArg = defaultEmptyOK;
    if (isNonnegativeInteger.arguments.length > 1)
        secondArg = isNonnegativeInteger.arguments[1];
    // The next line is a bit byzantine.  What it means is:
    // a) s must be a signed integer, AND
    // b) one of the following must be true:
    //    i)  s is empty and we are supposed to return true for
    //        empty strings
    //    ii) this is a number >= 0
    return (isSignedInteger(s, secondArg)
         && ( (isEmpty(s) && secondArg)  || (parseInt (s) >= 0) ) );
}

// isNegativeInteger (STRING s [, BOOLEAN emptyOK])
//
// Returns true if string s is an integer < 0.
function isNegativeInteger (s)
{
	var secondArg = defaultEmptyOK;
    if (isNegativeInteger.arguments.length > 1)
        secondArg = isNegativeInteger.arguments[1];
    // The next line is a bit byzantine.  What it means is:
    // a) s must be a signed integer, AND
    // b) one of the following must be true:
    //    i)  s is empty and we are supposed to return true for
    //        empty strings
    //    ii) this is a negative, not positive, number
    return (isSignedInteger(s, secondArg)
         && ( (isEmpty(s) && secondArg)  || (parseInt (s) < 0) ) );
}

// isNonpositiveInteger (STRING s [, BOOLEAN emptyOK])
//
// Returns true if string s is an integer <= 0.
function isNonpositiveInteger (s)
{
	var secondArg = defaultEmptyOK;
    if (isNonpositiveInteger.arguments.length > 1)
        secondArg = isNonpositiveInteger.arguments[1];
    // The next line is a bit byzantine.  What it means is:
    // a) s must be a signed integer, AND
    // b) one of the following must be true:
    //    i)  s is empty and we are supposed to return true for
    //        empty strings
    //    ii) this is a number <= 0
    return (isSignedInteger(s, secondArg)
         && ( (isEmpty(s) && secondArg)  || (parseInt (s) <= 0) ) );
}

// isFloat (STRING s [, BOOLEAN emptyOK])
//
// True if string s is an unsigned floating point (real) number.
function isFloat (s)
{
	var i;
    var seenDecimalPoint = false;
    if (isEmpty(s))
       if (isFloat.arguments.length == 1) return defaultEmptyOK;
       else return (isFloat.arguments[1] == true);
    if (s == decimalPointDelimiter) return false;
    // Search through string's characters one by one
    // until we find a non-numeric character.
    // When we do, return false; if we don't, return true.
    for (i = 0; i < s.length; i++)
    {
        // Check that current character is number.
        var c = s.charAt(i);
        if ((c == decimalPointDelimiter) && !seenDecimalPoint) seenDecimalPoint = true;
        else if (!isDigit(c)) return false;
    }
    // All characters are numbers.
    return true;
}

// isSignedFloat (STRING s [, BOOLEAN emptyOK])
//
// True if string s is a signed or unsigned floating point
// (real) number. First character is allowed to be + or -.
function isSignedFloat (s)
{
	if (isEmpty(s))
       if (isSignedFloat.arguments.length == 1) return defaultEmptyOK;
       else return (isSignedFloat.arguments[1] == true);
    else {
        var startPos = 0;
        var secondArg = defaultEmptyOK;
        if (isSignedFloat.arguments.length > 1)
            secondArg = isSignedFloat.arguments[1];
        // skip leading + or -
        if ( (s.charAt(0) == "-") || (s.charAt(0) == "+") )
           startPos = 1;
        return (isFloat(s.substring(startPos, s.length), secondArg))
    }
}

// isAlphabetic (STRING s [, BOOLEAN emptyOK])
//
// Returns true if string s is English letters
// (A .. Z, a..z) only.
function isAlphabetic (s)
{
	var i;
    if (isEmpty(s))
       if (isAlphabetic.arguments.length == 1) return defaultEmptyOK;
       else return (isAlphabetic.arguments[1] == true);
    // Search through string's characters one by one
    // until we find a non-alphabetic character.
    // When we do, return false; if we don't, return true.
    for (i = 0; i < s.length; i++)
    {
        // Check that current character is letter.
        var c = s.charAt(i);
        if (!isLetter(c))
        return false;
    }
    // All characters are letters.
    return true;
}


// isXAlphabetic (STRING s [, BOOLEAN emptyOK])
//
// Returns true if string s is English letters
// (A .. Z, a..z),space or '.
function isXAlphabetic (s)
{
	var i;
    if (isWhitespace(s))
       if (isXAlphabetic.arguments.length == 1) return defaultEmptyOK;
    else return (isXAlphabetic.arguments[1] == true);
    // Search through string's characters one by one
    // until we find a non-alphabetic character.
    // When we do, return false; if we don't, return true.
    for (i = 0; i < s.length; i++)
    {
        // Check that current character is letter.
        var c = s.charAt(i);
        if (!isLetter(c) && c != " " && c != "'")
        return false;
    }
    // All characters are letters.
    return true;
}

// isExtAlphabetic (STRING s [, BOOLEAN emptyOK])
//
// Returns true if string s is English letters
// (A .. Z, a..z) or spaces.
function isExtAlphabetic (s)
{
	var i;
    if (isWhitespace(s))
       if (isXAlphabetic.arguments.length == 1) return defaultEmptyOK;
    else return (isXAlphabetic.arguments[1] == true);
    // Search through string's characters one by one
    // until we find a non-alphabetic character.
    // When we do, return false; if we don't, return true.
    for (i = 0; i < s.length; i++)
    {
        // Check that current character is letter.
        var c = s.charAt(i);
        if (!isLetter(c) && c != " ")
        return false;
    }
    // All characters are letters.
    return true;
}


// isAlphanumeric (STRING s [, BOOLEAN emptyOK])
//
// Returns true if string s is English letters
// (A .. Z, a..z) and numbers only.
function isAlphanumeric (s)
{
	var i;
    if (isEmpty(s))
       if (isAlphanumeric.arguments.length == 1) return defaultEmptyOK;
       else return (isAlphanumeric.arguments[1] == true);
    // Search through string's characters one by one
    // until we find a non-alphanumeric character.
    // When we do, return false; if we don't, return true.
    for (i = 0; i < s.length; i++)
    {
        // Check that current character is number or letter.
        var c = s.charAt(i);
        if (! (isLetter(c) || isDigit(c) ) )
        return false;
    }
    // All characters are numbers or letters.
    return true;
}

// isXAlphanumeric (STRING s [, BOOLEAN emptyOK])
//
// Returns true if string s is English letters
// (A .. Z, a..z),space or ' and numbers only.
function isXAlphanumeric(s)
{
	var i;
    if (isWhitespace(s))
       if (isXAlphanumeric.arguments.length == 1) return defaultEmptyOK;
    else return (isXAlphanumeric.arguments[1] == true);
    // Search through string's characters one by one
    // until we find a non-alphabetic character.
    // When we do, return false; if we don't, return true.
    for (i = 0; i < s.length; i++)
    {
        // Check that current character is letter.
        var c = s.charAt(i);
        if ( !isDigit(c) && !isLetter(c) && c != " " && c != "'" )
        return false;
    }
    // All characters are letters.
    return true;
}

function isSpaceAlphanumeric(s)
{
	var i;
    if (isWhitespace(s))
       if (isXAlphanumeric.arguments.length == 1) return defaultEmptyOK;
    else return (isXAlphanumeric.arguments[1] == true);
    // Search through string's characters one by one
    // until we find a non-alphabetic character.
    // When we do, return false; if we don't, return true.
    for (i = 0; i < s.length; i++)
    {
        // Check that current character is letter.
        var c = s.charAt(i);
        if ( !isDigit(c) && !isLetter(c) && c != " ")
        return false;
    }
    // All characters are letters.
    return true;
}

// reformat (TARGETSTRING, STRING, INTEGER, STRING, INTEGER ... )
//
// Handy function for arbitrarily inserting formatting characters
// or delimiters of various kinds within TARGETSTRING.
// EXAMPLES:
//
// * To reformat a 10-digit U.S. phone number from "1234567890"
//   to "(123) 456-7890" make this function call:
//   reformat("1234567890", "(", 3, ") ", 3, "-", 4)
//
// * To reformat a 9-digit U.S. Social Security number from
//   "123456789" to "123-45-6789" make this function call:
//   reformat("123456789", "", 3, "-", 2, "-", 4)
// EXAMPLE:
//
// reformat (stripCharsNotInBag ("123 456 7890", digits),
//           "(", 3, ") ", 3, "-", 4)
function reformat (s)
{
	var arg;
    var sPos = 0;
    var resultString = "";
    for (var i = 1; i < reformat.arguments.length; i++) {
       arg = reformat.arguments[i];
       if (i % 2 == 1) resultString += arg;
       else {
           resultString += s.substring(sPos, sPos + arg);
           sPos += arg;
       }
    }
    return resultString;
}

// isUSPhoneNumber (STRING s [, BOOLEAN emptyOK])
//
// isUSPhoneNumber returns true if string s is a valid U.S. Phone
// Number.  Must be 10 digits.
function isUSPhoneNumber (s)
{
	if (isEmpty(s))
       if (isUSPhoneNumber.arguments.length == 1) return defaultEmptyOK;
       else return (isUSPhoneNumber.arguments[1] == true);
    return (isInteger(s))
}

// isEmail (STRING s [, BOOLEAN emptyOK])
//
// Email address must be of form a@b.c -- in other words:
// * there must be at least one character before the @
// * there must be at least one character before and after the .
// * the characters @ and . are both required
function isEmail (s)
{
	if (isEmpty(s))
       if (isEmail.arguments.length == 1) return defaultEmptyOK;
       else return (isEmail.arguments[1] == true);
    // is s whitespace?
    if (isWhitespace(s)) return false;
    // there must be >= 1 character before @, so we
    // start looking at character position 1
    // (i.e. second character)
    var i = 1;
    var sLength = s.length;
    // look for @
    while ((i < sLength) && (s.charAt(i) != "@"))
    { i++
    }
    if ((i >= sLength) || (s.charAt(i) != "@")) return false;
    else i += 2;
    // look for .
    while ((i < sLength) && (s.charAt(i) != "."))
    { i++
    }
    // there must be at least one character after the .
    if ((i >= sLength - 1) || (s.charAt(i) != ".")) return false;
    else return true;
}

// isYear (STRING s [, BOOLEAN emptyOK])
//
// isYear returns true if string s is a valid
// Year number.  Must be 2 or 4 digits only.
function isYear (s)
{
	if (isEmpty(s))
       if (isYear.arguments.length == 1) return defaultEmptyOK;
       else return (isYear.arguments[1] == true);
    if (!isNonnegativeInteger(s)) return false;
    return ((s.length == 2) || (s.length == 4));
}

// isIntegerInRange (STRING s, INTEGER a, INTEGER b [, BOOLEAN emptyOK])
//
// isIntegerInRange returns true if string s is an integer
// within the range of integer arguments a and b, inclusive.
function isIntegerInRange (s, a, b)
{
	if (isEmpty(s))
       if (isIntegerInRange.arguments.length == 1) return defaultEmptyOK;
       else return (isIntegerInRange.arguments[1] == true);
    // Catch non-integer strings to avoid creating a NaN below,
    // which isn't available on JavaScript 1.0 for Windows.
    if (!isInteger(s, false)) return false;
    // Now, explicitly change the type to integer via parseInt
    // so that the comparison code below will work both on
    // JavaScript 1.2 (which typechecks in equality comparisons)
    // and JavaScript 1.1 and before (which doesn't).
    var num = parseInt (s);
    return ((num >= a) && (num <= b));
}

// isMonth (STRING s [, BOOLEAN emptyOK])
//
// isMonth returns true if string s is a valid
// month number between 1 and 12.
function isMonth (s)
{
	if (isEmpty(s))
       if (isMonth.arguments.length == 1) return defaultEmptyOK;
       else return (isMonth.arguments[1] == true);
    return isIntegerInRange (s, 1, 12);
}

// isDay (STRING s [, BOOLEAN emptyOK])
//
// isDay returns true if string s is a valid
// day number between 1 and 31.
function isDay (s)
{
	if (isEmpty(s))
       if (isDay.arguments.length == 1) return defaultEmptyOK;
       else return (isDay.arguments[1] == true);
    return isIntegerInRange (s, 1, 31);
}

// daysInFebruary (INTEGER year)
//
// Given integer argument year,
// returns number of days in February of that year.
function daysInFebruary (year)
{
	// February has 29 days in any year evenly divisible by four,
    // EXCEPT for centurial years which are not also divisible by 400.
    return (  ((year % 4 == 0) && ( (!(year % 100 == 0)) || (year % 400 == 0) ) ) ? 29 : 28 );
}

// isDate (STRING year, STRING month, STRING day)
//
// isDate returns true if string arguments year, month, and day
// form a valid date.
function isDate (year, month, day)
{
	// catch invalid years (not 2- or 4-digit) and invalid months and days.
    if (! (isYear(year, false) && isMonth(month, false) && isDay(day, false))) return false;
    // Explicitly change type to integer to make code work in both
    // JavaScript 1.1 and JavaScript 1.2.
    var intYear = parseInt(year);
    var intMonth = parseInt(month);
    var intDay = parseInt(day);
    // catch invalid days, except for February
    if (intDay > daysInMonth[intMonth]) return false;
    if ((intMonth == 2) && (intDay > daysInFebruary(intYear))) return false;
    return true;
}



/* FUNCTIONS TO NOTIFY USER OF INPUT REQUIREMENTS OR MISTAKES. */

// Display prompt string s in status bar.
function prompt (s)
{   window.status = s }

// Display data entry prompt string s in status bar.
function promptEntry (s)
{   window.status = pEntryPrompt + s }


// Notify user that required field theField is empty.
// String s describes expected contents of theField.value.
// Put focus in theField and return false.
function warnEmpty (theField, s)
{
	theField.focus()
    alert(mPrefix + s + mSuffix)
    return false
}

// Notify user that contents of field theField are invalid.
// String s describes expected contents of theField.value.
// Put select theField, pu focus in it, and return false.
function warnInvalid (theField, s)
{
	alert(iPrefix + s + iSuffix)
	theField.focus()
	theField.select()
    return false
}

function warnfield (theField, s)
{
	alert(iPrefix + theField.name + iSuffix)
	theField.focus()
	theField.value = ""
    theField.focus()
    return false
}

// Notify user for a warning.
// String s describes warning message.
// Put select theField, pu focus in it, and return false.
function warnGeneric (theField, s)
{
	alert(s)
	theField.focus()
    theField.select()
    return false
}


/* FUNCTIONS TO INTERACTIVELY CHECK VARIOUS FIELDS. */
// checkInteger (TEXTFIELD theField [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is a valid Email.
function checkInteger (theField, emptyOK)
{
	if (checkInteger.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else if (!isInteger(theField.value))
       return warnInvalid (theField);
    else return true;
}


// checkString (TEXTFIELD theField, STRING s, [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is not all whitespace.
function checkString (theField, s, emptyOK)
{
	// Next line is needed on NN3 to avoid "undefined is not a number" error
    // in equality comparison below.
    if (checkString.arguments.length == 2) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    if (isWhitespace(theField.value))
       return warnEmpty (theField, s);
    else return true;
}


// checkPhone (TEXTFIELD theField [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is a valid US Phone.
function checkPhone(theField, emptyOK)
{
	if (checkPhone.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else
    {  var normalizedPhone = stripCharsInBag(theField.value, phoneNumberDelimiters)
       if (!isUSPhoneNumber(normalizedPhone, false))
          return warnInvalid (theField, iUSPhone);
       else
       {  // if you don't want to reformat as (123) 456-789, comment next line out
          //theField.value = reformatUSPhone(normalizedPhone)
          return true;
       }
    }
}

// checkInternationalPhone (TEXTFIELD theField [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is a valid International Phone.
function checkInternationalPhone (theField, emptyOK)
{
	if (checkInternationalPhone.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else
    {  if (!isInternationalPhoneNumber(theField.value, false))
          return warnInvalid (theField, iWorldPhone);
       else return true;
    }
}

// checkEmail (TEXTFIELD theField [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is a valid Email.
function checkEmail (theField, emptyOK, s)
{
	if (checkEmail.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else if (!isEmail(theField.value, false))
        if (checkEmail.length == 3) {
           return warnInvalid (theField, s);
        } else {
            return warnInvalid (theField, iEmail);
        }
    else return true;
}

// checkName (TEXTFIELD theField [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is a valid name.
function checkName (theField, emptyOK)
{
	if (checkName.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else if (!isXAlphabetic(theField.value, false))
       return warnInvalid (theField, iName);
    else return true;
}

// checkSpaceAlphanumeric (TEXTFIELD theField [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is a valid alphanumeric space name.
function checkSpaceAlphanumeric (theField, emptyOK)
{
	if (checkSpaceAlphanumeric.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else if (!isSpaceAlphanumeric(theField.value, false))
       return warnInvalid (theField, iName);
    else return true;
}

// checkUsrOrPwd (TEXTFIELD theField [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is a valid name.
function checkUsrOrPwd (theField, emptyOK, s)
{
	if (checkUsrOrPwd.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else if (!isAlphanumeric(theField.value, false)) {

        if (checkUsrOrPwd.length == 3) {
            return warnInvalid (theField, s);
        } else {
            return warnInvalid (theField, iName);
        }

       return warnInvalid (theField, iUser);
    } else
        return true;
}

// checkPwd (TEXTFIELD theField1 [, BOOLEAN emptyOK==false], TEXTFIELD theField2 [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is a valid name.
function checkPwd (theField1, theField2)
{
    if (theField1.value != theField2.value)
       return warnfield (theField1, iPwd);
    else return true;
}

// Check that string theField.value is a valid Year.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function checkYear (theField, emptyOK)
{
	if (checkYear.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    if (!isYear(theField.value, false))
       return warnInvalid (theField, iYear);
    else return true;
}

// Check that string theField.value is a valid Month.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function checkMonth (theField, emptyOK)
{
	if (checkMonth.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    if (!isMonth(theField.value, false))
       return warnInvalid (theField, iMonth);
    else return true;
}

// Check that string theField.value is a valid Day.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function checkDay (theField, emptyOK)
{
	if (checkDay.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    if (!isDay(theField.value, false))
       return warnInvalid (theField, iDay);
    else return true;
}

// checkDate (yearField, monthField, dayField, STRING labelString [, OKtoOmitDay==false])
//
// Check that yearField.value, monthField.value, and dayField.value
// form a valid date.
function checkDate (yearField, monthField, dayField, labelString, OKtoOmitDay)
{
	// Next line is needed on NN3 to avoid "undefined is not a number" error
    // in equality comparison below.
    if (checkDate.arguments.length == 4) OKtoOmitDay = false;
    if (!isYear(yearField.value)) return warnInvalid (yearField, iYear);
    if (!isMonth(monthField.value)) return warnInvalid (monthField, iMonth);
    if ( (OKtoOmitDay == true) && isEmpty(dayField.value) ) return true;
    else if (!isDay(dayField.value))
       return warnInvalid (dayField, iDay);
    if (isDate (yearField.value, monthField.value, dayField.value))
       return true;
    alert (iDatePrefix + labelString + iDateSuffix)
    return false
}