// BASIC DATA VALIDATION FUNCTIONS:
//
// isWhitespace (s)                    Check whether string s is empty or whitespace.
// isLetter (c)                        Check whether character c is an English letter 
// isDigit (c)                         Check whether character c is a digit 
// isLetterOrDigit (c)                 Check whether character c is a letter or digit.
// isInteger (s [,eok])                True if all characters in string s are numbers.
// isSignedInteger (s [,eok])          True if all characters in string s are numbers; leading + or - allowed.
// isPositiveInteger (s [,eok])        True if string s is an integer > 0.
// isNonnegativeInteger (s [,eok])     True if string s is an integer >= 0.
// isNegativeInteger (s [,eok])        True if s is an integer < 0.
// isNonpositiveInteger (s [,eok])     True if s is an integer <= 0.
// isFloat (s [,eok])                  True if string s is an unsigned floating point (real) number. (Integers also OK.)
// isSignedFloat (s [,eok])            True if string s is a floating point number; leading + or - allowed. (Integers also OK.)
// isAlphabetic (s [,eok])             True if string s is English letters 
// isAlphanumeric (s [,eok])           True if string s is English letters and numbers only.
// 
// isSSN (s [,eok])                    True if string s is a valid U.S. Social Security Number.
// isUSPhoneNumber (s [,eok])          True if string s is a valid U.S. Phone Number. 
// isInternationalPhoneNumber (s [,eok]) True if string s is a valid international phone number.
// isZIPCode (s [,eok])                True if string s is a valid U.S. ZIP code.
// isStateCode (s [,eok])              True if string s is a valid U.S. Postal Code
// isEmail (s [,eok])                  True if string s is a valid email address.
// isYear (s [,eok])                   True if string s is a valid Year number.
// isIntegerInRange (s, a, b [,eok])   True if string s is an integer between a and b, inclusive.
// isMonth (s [,eok])                  True if string s is a valid month between 1 and 12.
// isDay (s [,eok])                    True if string s is a valid day between 1 and 31.
// daysInFebruary (year)               Returns number of days in February of that year.
// isDate (year, month, day)           True if string arguments form a valid date.


// FUNCTIONS TO REFORMAT DATA:
//
// stripCharsInBag (s, bag)            Removes all characters in string bag from string s.
// stripCharsNotInBag (s, bag)         Removes all characters NOT in string bag from string s.
// stripWhitespace (s)                 Removes all whitespace characters from s.
// stripInitialWhitespace (s)          Removes initial (leading) whitespace characters from s.
// reformat (TARGETSTRING, STRING,     Function for inserting formatting characters or
//   INTEGER, STRING, INTEGER ... )       delimiters into TARGETSTRING.                                       
// reformatZIPCode (ZIPString)         If 9 digits, inserts separator hyphen.
// reformatSSN (SSN)                   Reformats as 123-45-6789.
// reformatUSPhone (USPhone)           Reformats as (123) 456-789.


// FUNCTIONS TO PROMPT USER:
//
// prompt (s)                          Display prompt string s in status bar.
// promptEntry (s)                     Display data entry prompt string s in status bar.
// warnEmpty (theField, s)             Notify user that required field theField is empty.
// warnInvalid (theField, s)           Notify user that contents of field theField are invalid.


// FUNCTIONS TO INTERACTIVELY CHECK FIELD CONTENTS:
//
// checkString (theField, s [,eok])    Check that theField.value is not empty or all whitespace.
// checkStateCode (theField)           Check that theField.value is a valid U.S. state code.
// checkZIPCode (theField [,eok])      Check that theField.value is a valid ZIP code.
// checkUSPhone (theField [,eok])      Check that theField.value is a valid US Phone.
// checkInternationalPhone (theField [,eok])  Check that theField.value is a valid International Phone.
// checkEmail (theField [,eok])        Check that theField.value is a valid Email.
// checkSSN (theField [,eok])          Check that theField.value is a valid SSN.
// checkYear (theField [,eok])         Check that theField.value is a valid Year.
// checkMonth (theField [,eok])        Check that theField.value is a valid Month.
// checkDay (theField [,eok])          Check that theField.value is a valid Day.
// checkDate (yearField, monthField, dayField, labelString, OKtoOmitDay)
//                                     Check that field values form a valid date.
// getRadioButtonValue (radio)         Get checked value from radio button.
// checkCreditCard (radio, theField)   Validate credit card info.


// CREDIT CARD DATA VALIDATION FUNCTIONS
// 
// isCreditCard (st)              True if credit card number passes the Luhn Mod-10 test.
// isVisa (cc)                    True if string cc is a valid VISA number.
// isMasterCard (cc)              True if string cc is a valid MasterCard number.
// isAmericanExpress (cc)         True if string cc is a valid American Express number.
// isDinersClub (cc)              True if string cc is a valid Diner's Club number.
// isCarteBlanche (cc)            True if string cc is a valid Carte Blanche number.
// isDiscover (cc)                True if string cc is a valid Discover card number.
// isEnRoute (cc)                 True if string cc is a valid enRoute card number.
// isJCB (cc)                     True if string cc is a valid JCB card number.
// isAnyCard (cc)                 True if string cc is a valid card number for any of the accepted types.
// isCardMatch (Type, Number)     True if Number is valid for credic card of type Type.

// VARIABLE DECLARATIONS

datetoday = new Date();
var digits = "0123456789";
var lowercaseLetters = "abcdefghijklmnopqrstuvwxyz"
var uppercaseLetters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
var whitespace = " \t\n\r";
var decimalPointDelimiter = "."
var phoneNumberDelimiters = "()- ";
var validUSPhoneChars = digits + phoneNumberDelimiters;
var validWorldPhoneChars = digits + phoneNumberDelimiters + "+";
var SSNDelimiters = "- ";
var validSSNChars = digits + SSNDelimiters;
var digitsInSocialSecurityNumber = 9;
var digitsInUSPhoneNumber = 10;
var ZIPCodeDelimiters = "-";
var ZIPCodeDelimeter = "-"
var validZIPCodeChars = digits + ZIPCodeDelimiters
var digitsInZIPCode1 = 5
var digitsInZIPCode2 = 9
var creditCardDelimiters = " "

var mPrefix = "You did not enter a value into the "
var mSuffix = " field. This is a required field. Please enter it now."

var sUSLastName = "Last Name"
var sUSFirstName = "First Name"
var sWorldLastName = "Family Name"
var sWorldFirstName = "Given Name"
var sTitle = "Title"
var sCompanyName = "Company Name"
var sUSAddress = "Street Address"
var sWorldAddress = "Address"
var sCity = "City"
var sStateCode = "State Code"
var sWorldState = "State, Province, or Prefecture"
var sCountry = "Country"
var sZIPCode = "ZIP Code"
var sWorldPostalCode = "Postal Code"
var sPhone = "Phone Number"
var sFax = "Fax Number"
var sDateOfBirth = "Date of Birth"
var sExpirationDate = "Expiration Date"
var sEmail = "Email"
var sSSN = "Social Security Number"
var sCreditCardNumber = "Credit Card Number"
var sOtherInfo = "Other Information"

// i is an abbreviation for "invalid"

var iStateCode = "This field must be a valid two character U.S. state abbreviation (like CA for California). Please reenter it now."
var iZIPCode = "This field must be a 5 or 9 digit U.S. ZIP Code (like 94043). Please reenter it now."
var iUSPhone = "This field must be a 10 digit U.S. phone number (like 415 555 1212). Please reenter it now."
var iWorldPhone = "This field must be a valid international phone number. Please reenter it now."
var iSSN = "This field must be a 9 digit U.S. social security number (like 123 45 6789). Please reenter it now."
var iEmail = "This field must be a valid email address (like Someone@somewhere.com). Please reenter it now."
var iCreditCardPrefix = "This is not a valid "
var iCreditCardSuffix = " credit card number. (Click the link on this form to see a list of sample numbers.) Please reenter it now."
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 4 digit year number.  Please reenter it now."
var iDatePrefix = "The Month and Year for "
var iDateSuffix = " do not form a valid date.  Please reenter them now."

// p is an abbreviation for "prompt"

var pEntryPrompt = "Please enter a "
var pStateCode = "2 character code (like CA)."
var pZIPCode = "5 or 9 digit U.S. ZIP Code (like 94043)."
var pUSPhone = "10 digit U.S. phone number (like 415 555 1212)."
var pWorldPhone = "international phone number."
var pSSN = "9 digit U.S. social security number (like 123 45 6789)."
var pEmail = "valid email address (like foo@bar.com)."
var pCreditCard = "valid credit card number."
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) {
   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;

var USStateCodeDelimiter = "|";
var USStateCodes = "AL|AK|AS|AZ|AR|CA|CO|CT|DE|DC|FM|FL|GA|GU|HI|ID|IL|IN|IA|KS|KY|LA|ME|MH|MD|MA|MI|MN|MS|MO|MT|NE|NV|NH|NJ|NM|NY|NC|ND|MP|OH|OK|OR|PW|PA|PR|RI|SC|SD|TN|TX|UT|VT|VI|VA|WA|WV|WI|WY|AE|AA|AE|AE|AP"

function isEmpty(s)
{   return ((s == null) || (s.length == 0))
}

function isWhitespace (s)

{   var i;

    // Is s empty?
    if (isEmpty(s)) 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;
}

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;
}

function stripCharsNotInBag (s, bag)

{   var i;
    var 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;
}

function stripWhitespace (s)

{   return stripCharsInBag (s, whitespace)
}

function charInString (c, s)
{   for (i = 0; i < s.length; i++)
    {   if (s.charAt(i) == c) return true;
    }
    return false
}

function stripInitialWhitespace (s)

{   var i = 0;

    while ((i < s.length) && charInString (s.charAt(i), whitespace))
       i++;
    
    return s.substring (i, s.length);
}

function isLetter (c)
{   return ( ((c >= "a") && (c <= "z")) || ((c >= "A") && (c <= "Z")) )
}

function isDigit (c)
{   return ((c >= "0") && (c <= "9"))
}

function isLetterOrDigit (c)
{   return (isLetter(c) || isDigit(c))
}

// 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);

    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;
}
// 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))
    }
}

function isPositiveInteger (s)
{   var secondArg = defaultEmptyOK;

    if (isPositiveInteger.arguments.length > 1)
        secondArg = isPositiveInteger.arguments[1];

    return (isSignedInteger(s, secondArg)
         && ( (isEmpty(s) && secondArg)  || (parseInt (s) > 0) ) );
}

function isNonnegativeInteger (s)
{   var secondArg = defaultEmptyOK;

    if (isNonnegativeInteger.arguments.length > 1)
        secondArg = isNonnegativeInteger.arguments[1];

    return (isSignedInteger(s, secondArg)
         && ( (isEmpty(s) && secondArg)  || (parseInt (s) >= 0) ) );
}

function isNegativeInteger (s)
{   var secondArg = defaultEmptyOK;

    if (isNegativeInteger.arguments.length > 1)
        secondArg = isNegativeInteger.arguments[1];

    return (isSignedInteger(s, secondArg)
         && ( (isEmpty(s) && secondArg)  || (parseInt (s) < 0) ) );
}

function isNonpositiveInteger (s)
{   var secondArg = defaultEmptyOK;

    if (isNonpositiveInteger.arguments.length > 1)
        secondArg = isNonpositiveInteger.arguments[1];

    return (isSignedInteger(s, secondArg)
         && ( (isEmpty(s) && secondArg)  || (parseInt (s) <= 0) ) );
}

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;

    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;
}
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))
    }
}

function isAlphabetic (s)

{   var i;

    if (isEmpty(s)) 
       if (isAlphabetic.arguments.length == 1) return defaultEmptyOK;
       else return (isAlphabetic.arguments[1] == 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;
}

function isAlphanumeric (s)

{   var i;

    if (isEmpty(s)) 
       if (isAlphanumeric.arguments.length == 1) return defaultEmptyOK;
       else return (isAlphanumeric.arguments[1] == 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;
}

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;
}

function isSSN (s)
{   if (isEmpty(s)) 
       if (isSSN.arguments.length == 1) return defaultEmptyOK;
       else return (isSSN.arguments[1] == true);
    return (isInteger(s) && s.length == digitsInSocialSecurityNumber)
}

function isUSPhoneNumber (s)
{   if (isEmpty(s)) 
       if (isUSPhoneNumber.arguments.length == 1) return defaultEmptyOK;
       else return (isUSPhoneNumber.arguments[1] == true);
    return (isInteger(s) && s.length == digitsInUSPhoneNumber)
}

function isInternationalPhoneNumber (s)
{   if (isEmpty(s)) 
       if (isInternationalPhoneNumber.arguments.length == 1) return defaultEmptyOK;
       else return (isInternationalPhoneNumber.arguments[1] == true);
    return (isPositiveInteger(s))
}

function isZIPCode (s)
{  if (isEmpty(s)) 
       if (isZIPCode.arguments.length == 1) return defaultEmptyOK;
       else return (isZIPCode.arguments[1] == true);
   return (isInteger(s) && 
            ((s.length == digitsInZIPCode1) ||
             (s.length == digitsInZIPCode2)))
}

function isStateCode(s)
{   if (isEmpty(s)) 
       if (isStateCode.arguments.length == 1) return defaultEmptyOK;
       else return (isStateCode.arguments[1] == true);
    return ( (USStateCodes.indexOf(s) != -1) &&
             (s.indexOf(USStateCodeDelimiter) == -1) )
}

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;
    
    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;
}

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 == 4);
}

function isIntegerInRange (s, a, b)
{   if (isEmpty(s)) 
       if (isIntegerInRange.arguments.length == 1) return defaultEmptyOK;
       else return (isIntegerInRange.arguments[1] == true);

    if (!isInteger(s, false)) return false;

    var num = parseInt (s);
    return ((num >= a) && (num <= b));
}

function isMonth (s)
{   if (isEmpty(s)) 
       if (isMonth.arguments.length == 1) return defaultEmptyOK;
       else return (isMonth.arguments[1] == true);
    return isIntegerInRange (s, 1, 12);
}

function isDay (s)
{   if (isEmpty(s)) 
       if (isDay.arguments.length == 1) return defaultEmptyOK;
       else return (isDay.arguments[1] == true);   
    return isIntegerInRange (s, 1, 31);
}

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 );
}

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;
}

function prompt (s)
{   window.status = s
}

function promptEntry (s)
{   window.status = pEntryPrompt + s
}

function warnEmpty (theField, s)
{   theField.focus()
    alert(mPrefix + s + mSuffix)
    return false
}

function warnInvalid (theField, s)
{   theField.focus()
    theField.select()
    alert(s)
    return false
}

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;
}

function checkStateCode (theField, emptyOK)
{   if (checkStateCode.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else
    {  theField.value = theField.value.toUpperCase();
       if (!isStateCode(theField.value, false)) 
          return warnInvalid (theField, iStateCode);
       else return true;
    }
}

function reformatZIPCode (ZIPString)
{   if (ZIPString.length == 5) return ZIPString;
    else return (reformat (ZIPString, "", 5, "-", 4));
}

function checkZIPCode (theField, emptyOK)
{   if (checkZIPCode.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else
    { var normalizedZIP = stripCharsInBag(theField.value, ZIPCodeDelimiters)
      if (!isZIPCode(normalizedZIP, false)) 
         return warnInvalid (theField, iZIPCode);
      else 
      {  // if you don't want to insert a hyphen, comment next line out
         theField.value = reformatZIPCode(normalizedZIP)
         return true;
      }
    }
}

function reformatUSPhone (USPhone)
{   return (reformat (USPhone, "(", 3, ") ", 3, "-", 4))
}

function checkUSPhone (theField, emptyOK)
{   if (checkUSPhone.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;
       }
    }
}

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;
    }
}

function checkEmail (theField, emptyOK)
{   if (checkEmail.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else if (!isEmail(theField.value, false)) 
       return warnInvalid (theField, iEmail);
    else return true;
}

function reformatSSN (SSN)
{   return (reformat (SSN, "", 3, "-", 2, "-", 4))
}

function checkSSN (theField, emptyOK)
{   if (checkSSN.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else
    {  var normalizedSSN = stripCharsInBag(theField.value, SSNDelimiters)
       if (!isSSN(normalizedSSN, false)) 
          return warnInvalid (theField, iSSN);
       else 
       {  // if you don't want to reformats as 123-456-7890, comment next line out
          theField.value = reformatSSN(normalizedSSN)
          return true;
       }
    }
}

function checkYear (theField, emptyOK)
{   yeartoday = datetoday.getYear()
    yeartoday = yeartoday + 1900;
    if (checkYear.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    if (!isYear(theField.value, false))
       return warnInvalid (theField, iYear);
	if (theField.value < yeartoday)
	   return warnInvalid (theField, "Year has expired.  Please re-enter.");
    else return true;
}

function checkMonth (theField, emptyOK)
{   monthtoday = datetoday.getMonth() + 1
    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;
}

function checkDay (theField, emptyOK)
{   daytoday = datetoday.getDay()
    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;
}

function checkDate (yearField, monthField, dayField, labelString, OKtoOmitDay)
{   yeartoday = datetoday.getYear();
    yeartoday = yeartoday + 1900;
	monthtoday = datetoday.getMonth() + 1;
    // 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, 1))
	   if (yearField.value > yeartoday) return true;
	   else if (yearField.value == yeartoday)
            if (monthField.value >= monthtoday)
	           return true;
    alert (iDatePrefix + labelString + iDateSuffix)
    return false
}

function getRadioButtonValue (radio)
{   for (var i = 0; i < radio.length; i++)
    {   if (radio[i].checked) { break }
    }
    return radio[i].value
}

function checkCreditCard (radio, theField)
{   var cardType = getRadioButtonValue (radio)
    var normalizedCCN = stripCharsInBag(theField.value, creditCardDelimiters)
    if (!isCardMatch(cardType, normalizedCCN)) 
       return warnInvalid (theField, iCreditCardPrefix + cardType + iCreditCardSuffix);
    else 
    {  theField.value = normalizedCCN
       return true
    }
}

function isCreditCard(st) {
  // Encoding only works on cards with less than 19 digits
  if (st.length > 19)
    return (false);

  sum = 0; mul = 1; l = st.length;
  for (i = 0; i < l; i++) {
    digit = st.substring(l-i-1,l-i);
    tproduct = parseInt(digit ,10)*mul;
    if (tproduct >= 10)
      sum += (tproduct % 10) + 1;
    else
      sum += tproduct;
    if (mul == 1)
      mul++;
    else
      mul--;
  }
  if ((sum % 10) == 0)
    return (true);
  else
    return (false);

} // END FUNCTION isCreditCard()

function isVisa(cc)
{
  if (((cc.length == 16) || (cc.length == 13)) &&
      (cc.substring(0,1) == 4))
    return isCreditCard(cc);
  return false;
}  // END FUNCTION isVisa()

function isMasterCard(cc)
{
  firstdig = cc.substring(0,1);
  seconddig = cc.substring(1,2);
  if ((cc.length == 16) && (firstdig == 5) &&
      ((seconddig >= 1) && (seconddig <= 5)))
    return isCreditCard(cc);
  return false;

} // END FUNCTION isMasterCard()

function isAmericanExpress(cc)
{
  firstdig = cc.substring(0,1);
  seconddig = cc.substring(1,2);
  if ((cc.length == 15) && (firstdig == 3) &&
      ((seconddig == 4) || (seconddig == 7)))
    return isCreditCard(cc);
  return false;

} // END FUNCTION isAmericanExpress()

function isDinersClub(cc)
{
  firstdig = cc.substring(0,1);
  seconddig = cc.substring(1,2);
  if ((cc.length == 14) && (firstdig == 3) &&
      ((seconddig == 0) || (seconddig == 6) || (seconddig == 8)))
    return isCreditCard(cc);
  return false;
}

function isCarteBlanche(cc)
{
  return isDinersClub(cc);
}

function isDiscover(cc)
{
  first4digs = cc.substring(0,4);
  if ((cc.length == 16) && (first4digs == "6011"))
    return isCreditCard(cc);
  return false;

} // END FUNCTION isDiscover()

function isEnRoute(cc)
{
  first4digs = cc.substring(0,4);
  if ((cc.length == 15) &&
      ((first4digs == "2014") ||
       (first4digs == "2149")))
    return isCreditCard(cc);
  return false;
}

function isJCB(cc)
{
  first4digs = cc.substring(0,4);
  if ((cc.length == 16) &&
      ((first4digs == "3088") ||
       (first4digs == "3096") ||
       (first4digs == "3112") ||
       (first4digs == "3158") ||
       (first4digs == "3337") ||
       (first4digs == "3528")))
    return isCreditCard(cc);
  return false;

} // END FUNCTION isJCB()

function isAnyCard(cc)
{
  if (!isCreditCard(cc))
    return false;
  if (!isMasterCard(cc) && !isVisa(cc) && !isAmericanExpress(cc) && !isDinersClub(cc) &&
      !isDiscover(cc) && !isEnRoute(cc) && !isJCB(cc)) {
    return false;
  }
  return true;

} // END FUNCTION isAnyCard()

function isCardMatch (cardType, cardNumber)
{

	cardType = cardType.toUpperCase();
	var doesMatch = true;

	if ((cardType == "VISA") && (!isVisa(cardNumber)))
		doesMatch = false;
	if ((cardType == "MASTERCARD") && (!isMasterCard(cardNumber)))
		doesMatch = false;
	if ( ( (cardType == "AMERICANEXPRESS") || (cardType == "AMEX") )
                && (!isAmericanExpress(cardNumber))) doesMatch = false;
	if ((cardType == "DISCOVER") && (!isDiscover(cardNumber)))
		doesMatch = false;
	if ((cardType == "JCB") && (!isJCB(cardNumber)))
		doesMatch = false;
	if ((cardType == "DINERS") && (!isDinersClub(cardNumber)))
		doesMatch = false;
	if ((cardType == "CARTEBLANCHE") && (!isCarteBlanche(cardNumber)))
		doesMatch = false;
	if ((cardType == "ENROUTE") && (!isEnRoute(cardNumber)))
		doesMatch = false;
	return doesMatch;

}  // END FUNCTION CardMatch()

function checkHolderName (theField)
{
   if (isEmpty(theField.value))
      return warnInvalid (theField, "Account Holder's Name Required to Complete Transaction...Please Enter");
   return true;
}

function checkBankName (theField)
{
   if (isEmpty(theField.value))
      return warnInvalid (theField, "Bank Name on Check Required to Complete Transaction...Please Enter");
   return true;
}

function checkBankCity (theField)
{
   if (isEmpty(theField.value))
      return warnInvalid (theField, "Bank City Required to Complete Transaction...Please Enter");
   return true;
}

function checkBankState (theField)
{
   if (isEmpty(theField.value))
      return warnInvalid (theField, "Bank State on Check Required to Complete Transaction...Please Enter");
   return true;
}

function checkCheckNo (theField)
{   if (isEmpty(theField.value))
       return warnInvalid (theField, "Check Number Required...Please Enter");
	if (!isInteger(theField.value,false))
       return warnInvalid (theField, "Check Number needs to consist of numbers between 0-9");
    return true;
}

function checkBankNo (theField)
{   if (isEmpty(theField.value))
       return warnInvalid (theField, "Bank Number Required...Please Enter");
    if (!isInteger(theField.value,false))
       return warnInvalid (theField, "Bank Number needs to consist of numbers between 0-9");
    if (theField.length < 2)
       return warnInvalid (theField, "Bank Number needs to be 1 or 2 digits.");
    return true;
}

function checkAccountNo (theField)
{   if (!isInteger(theField.value,false))
       return warnInvalid (theField, "Account Number needs to consist of numbers between 0-9");
    return true;
}

function checkTransitNo (theField)
{   if (!isInteger(theField.value,false))
       return warnInvalid (theField, "Transit Number needs to consist of numbers between 0-9");
    if (theField.value.length == 9)
	   return true;
	  else
	    return warnInvalid (theField, "Transit Number needs to be 9 digits.");
    return true;
}

function checkDigSignature (theField)
{
   if (isEmpty(theField.value))
      return warnInvalid (theField, "Digital Signature Required to Complete Transaction...Please Enter");
   return true;
}

function checkIfEmpty (theField)
{
   if (isEmpty(theField.value))
      return warnInvalid (theField, "Required Field...Please Enter");
   return true;
}