// FormChek.js



// VARIABLE DECLARATIONS

var digits = "0123456789";

var lowercaseLetters = "abcdefghijklmnopqrstuvwxyz"

var uppercaseLetters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"


// 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;

// U.S. phone numbers have 10 digits.
// They are formatted as 123 456 7890 or (123) 456-7890.
var digitsInUSPhoneNumber = 10;



// non-digit characters which are allowed in ZIP Codes
var ZIPCodeDelimiters = "-";



// our preferred delimiter for reformatting ZIP Codes
var ZIPCodeDelimeter = "-"



// U.S. ZIP codes have 5 or 9 digits.
// They are formatted as 12345 or 12345-6789.
var digitsInZIPCode1 = 5
var digitsInZIPCode2 = 9


// non-digit characters which are allowed in credit card numbers
var creditCardDelimiters = " "


// CONSTANT STRING DECLARATIONS

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 sTitle = "Title"
var sCompanyName = "Company Name"
var sUSAddress = "Street Address"
var sCity = "City"
var sStateCode = "State Code"
var sWorldState = "State, Province, or Prefecture"
var sCountry = "Country"
var sZIPCode = "ZIP Code"
var sPhone = "Phone Number"
var sFax = "Fax Number"
var sExpirationDate = "Expiration Date"
var sEmail = "Email"
var sCreditCardNumber = "Credit Card Number"
var sOtherInfo = "Other Information"



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 iEmail = "This field must be a valid email address (like foo@bar.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 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."


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 pUS = "10 digit U.S.  number (like 415 555 1212)."
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) {

//   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;   
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;




// Valid U.S. Postal Codes for states, territories, armed forces, etc.


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"




// Check whether string s is empty.

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


function isWhitespace (s)

{   var i;

    if (isEmpty(s)) return true;

    for (i = 0; i < s.length; i++)
    {   
         var c = s.charAt(i);

        if (whitespace.indexOf(c) == -1) return false;
    }

    return true;
}

function stripCharsInBag (s, bag)

{   var i;
    var returnString = "";

    for (i = 0; i < s.length; i++)
    {   
        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++)
    {   
        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))
}



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++)
    {   

        var c = s.charAt(i);

        if (!isDigit(c)) return false;
    }


    return 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++)
    {   
          var c = s.charAt(i);

        if ((c == decimalPointDelimiter) && !seenDecimalPoint) seenDecimalPoint = true;
        else if (!isDigit(c)) return false;
    }

    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];

        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++)
    {   
        var c = s.charAt(i);

        if (!isLetter(c))
        return false;
    }

    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++)
    {   
       
        var c = s.charAt(i);

        if (! (isLetter(c) || isDigit(c) ) )
        return false;
    }

    
    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 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 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);
   
    if (isWhitespace(s)) return false;
    
    var i = 1;
    var sLength = s.length;

    while ((i < sLength) && (s.charAt(i) != "@"))
    { i++
    }

    if ((i >= sLength) || (s.charAt(i) != "@")) return false;
    else i += 2;


    while ((i < sLength) && (s.charAt(i) != "."))
    { i++
    }

   
    if ((i >= sLength - 1) || (s.charAt(i) != ".")) return false;
    else return true;
}




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 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)
    this.focus()
    return false
}



function checkString (theField, s, emptyOK)
{   
    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 
      {  
         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 
       {  
          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;
}



// Get checked value from radio button.

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




// Validate credit card info.

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) {
 
  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);

} 



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;

} 






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;

} 



/*  ================================================================
    FUNCTION:  isAnyCard()
 
    INPUT:     cc - a string representing a credit card number

    RETURNS:  true, if the credit card number is any valid credit
		    card number for any of the accepted card types.
		    
	      false, otherwise
    ================================================================ */

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()
 
    INPUT:    cardType - a string representing the credit card type
	      cardNumber - a string representing a credit card number

    RETURNS:  true, if the credit card number is valid for the particular
	      credit card type given in "cardType".
		    
	      false, otherwise
    ================================================================ */

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;

	return doesMatch;

}  // END FUNCTION CardMatch()




function IsCC (st) {
    return isCreditCard(st);
}

function IsVisa (cc)  {
  return isVisa(cc);
}

function IsVISA (cc)  {
  return isVisa(cc);
}

function IsMasterCard (cc)  {
  return isMasterCard(cc);
}

function IsMastercard (cc)  {
  return isMasterCard(cc);
}

function IsMC (cc)  {
  return isMasterCard(cc);
}

function IsAmericanExpress (cc)  {
  return isAmericanExpress(cc);
}

function IsAmEx (cc)  {
  return isAmericanExpress(cc);
}



function IsAnyCard(cc)  {
  return isAnyCard(cc);
}

function IsCardMatch (cardType, cardNumber)  {
  return isCardMatch (cardType, cardNumber);
}