var sErrorMessage = "You must fill in these fields before you continue.\r\n";
var bErrorOccurred = false; // set by AddErrorMsg function
var digits = "0123456789";
var whitespace = " \t\n\r";
var bSubmitted = false;

function ErrorMessage() {
    var sTmpErrorMessage = sErrorMessage;
    sErrorMessage = "You must fill in these fields before you continue.\r\n";
    return sTmpErrorMessage;
}

function AddErrorMsg(sMsg) {
    sErrorMessage = sErrorMessage.concat(sMsg, "\r\n");
    bErrorOccurred = true;
}

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

function bFieldPresent(name) {
	return (!isEmpty(name));
}

function isEmail(s) {

    var sArray1, sArray2;
    var bPassed = false;

    sArray1 = s.split("@")
    if (sArray1.length == 2) {
        if (sArray1[0].length > 0) {
            if (sArray1[1].length > 2) {
                sArray2 = sArray1[1].split(".")
                if (sArray2.length > 1) {
                    if (sArray2[0].length > 0) {
                        if (sArray2[1].length > 0) {
                            bPassed = true;
                        }
                    }
                }
            }
        }
    }    
    return bPassed;
}

function bCreditCardDateOK(sMonth, sYear) {

	var right_now = new Date();
	var nEnteredExpDate = 0;    // YYYYMM format
	var nCurrentDate = 0;       // YYYYMM format
	var bErrorOccurred = false;

    if (isWhitespace(sMonth) || isWhitespace(sYear)) {
        bErrorOccurred = true;
    } else {
    
        nCurrentDate = right_now.getFullYear() * 100 + right_now.getMonth() + 1;
        nEnteredExpDate = parseInt(sYear, 10) * 100 + parseInt(sMonth, 10);
        
        if (nCurrentDate > nEnteredExpDate) 
        {
            return false;
    	}
    	else
        {
            return true;
    	}
    }
}

function bCreditCardOK(sCardNumber) {
    
    var sJustNumeric;
    var bOK = false;
    var nFirstDigit;
    var nFirstTwoDigits;
    var nLenToCheck;
    if (!isCreditCard(sCardNumber))
	{
		return false;	
	}
    if (bFieldPresent(sCardNumber)) {
        sJustNumeric = sCullChars(sCardNumber, digits);
        sCardNumber = sJustNumeric;
        nFirstDigit = parseInt(sJustNumeric.charAt(0), 10);
        nFirstTwoDigits = parseInt(sJustNumeric.substr(0, 2), 10);
        if (3 <= nFirstDigit && nFirstDigit <= 6) {
            if (nFirstTwoDigits == 37) {
                nLenToCheck = 15;
            } else {
                nLenToCheck = 16;
            }
            if (sJustNumeric.length == nLenToCheck) {
                bOK = true;
            }
        }
    }
    return bOK;
}

function isCreditCard(st) {
    // Encoding only works on cards with less than 19 digits
    if (st.length > 19)
        return (true);
    var i;
    var sum = 0; 
    var mul = 1; 
    var len = st.length;
    var digit;
    
    for (i = 0; i < len; i++) {
        digit = st.substring(len - i - 1, len - i);
        tproduct = parseInt(digit, 10) * mul;
        if (tproduct >= 10)
            sum += (tproduct % 10) + 1;
        else
            sum += tproduct;
        if (mul == 1)
            mul++;
        else
            mul--;
    }
    return ((sum % 10) == 0)
}

function bZipCodeOK(sZipCode) {

    // Good for US only
    
    var sJustNumeric;
    var bOK = false;
    var aArray;
    var aLengths = new Array(5, 4);
    var i;
    var nTotalLength = 0;
    var nArrayLen;

    if (bFieldPresent(sZipCode)) {
        aArray = sZipCode.split("-");
        nArrayLen = aArray.length;
        if (nArrayLen > 2) {
            nArrayLen = 2;
        }
        for (i = 0; i < nArrayLen; i++) {
            aArray[i] = sCullChars(aArray[i], digits);
            nTotalLength += aLengths[i];
        }
        nTotalLength += nArrayLen - 1;
        sJustNumeric = aArray[0];
        if (nArrayLen > 1) {
            if (aArray[0].length > 0 && aArray[1].length > 0) {
                sJustNumeric += "-" + aArray[1];
            } else {
                sJustNumeric += aArray[1];
            }
        }
        sZipCode = sJustNumeric;
        if (sJustNumeric.length == nTotalLength) {
            var bOK = true;
        }
    }
    return bOK;
}

function sCullChars(sText, sCharsToCull) {
    
    var i;
    var sResult = "";
    
    for (i = 0; i < sText.length; i++) {
        if (sCharsToCull.indexOf(sText.charAt(i)) != -1) {
            sResult += sText.charAt(i);
        }
    }
    return sResult;
}

//  check for valid numeric strings	
function IsNumeric(strString) {

   var strValidChars = "0123456789";
   var strChar;
   var blnResult = true;

   //  test strString consists of valid characters listed above
   for (i = 0; i < strString.length && blnResult == true; i++) {
      strChar = strString.charAt(i);
      if (strValidChars.indexOf(strChar) == -1) {
         blnResult = false;
         break;
      }
   }
   return blnResult;
}

function isWhitespace(s) {

    var i;
    var c;

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

    // All characters are whitespace.
    return true;
}





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

    RETURNS:  true, if the credit card number is a valid VISA number.
		    
	      false, otherwise

    Sample number: 4111 1111 1111 1111 (16 digits)
    ================================================================ */

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()
 
    INPUT:     cc - a string representing a credit card number

    RETURNS:  true, if the credit card number is a valid MasterCard
		    number.
		    
	      false, otherwise

    Sample number: 5500 0000 0000 0004 (16 digits)
    ================================================================ */

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()
 
    INPUT:     cc - a string representing a credit card number

    RETURNS:  true, if the credit card number is a valid American
		    Express number.
		    
	      false, otherwise

    Sample number: 340000000000009 (15 digits)
    ================================================================ */

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()
 
    INPUT:     cc - a string representing a credit card number

    RETURNS:  true, if the credit card number is a valid Diner's
		    Club number.
		    
	      false, otherwise

    Sample number: 30000000000004 (14 digits)
    ================================================================ */

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()
 
    INPUT:     cc - a string representing a credit card number

    RETURNS:  true, if the credit card number is a valid Carte
		    Blanche number.
		    
	      false, otherwise
    ================================================================ */

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




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

    RETURNS:  true, if the credit card number is a valid Discover
		    card number.
		    
	      false, otherwise

    Sample number: 6011000000000004 (16 digits)
    ================================================================ */

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

} // END FUNCTION isDiscover()





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

    RETURNS:  true, if the credit card number is a valid enRoute
		    card number.
		    
	      false, otherwise

    Sample number: 201400000000009 (15 digits)
    ================================================================ */

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



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

    RETURNS:  true, if the credit card number is a valid JCB
		    card number.
		    
	      false, otherwise
    ================================================================ */

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()
 
    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;
	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()




/*  ================================================================
    The below stub functions are retained for backward compatibility
    with the original LivePayment code so that it should be possible
    in principle to swap in this new module as a replacement for the  
    older module without breaking existing code.  (There are no
    guarantees, of course, but it should work.)

    When writing new code, do not use these stub functions; use the
    functions defined above.
    ================================================================ */

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 IsDinersClub (cc)  {
  return isDinersClub(cc);
}

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

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

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

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

function IsDiscover (cc)  {
  return isDiscover(cc);
}

function IsEnRoute (cc)  {
  return isEnRoute(cc);
}

function IsenRoute (cc)  {
  return isEnRoute(cc);
}

function IsJCB (cc)  {
  return isJCB(cc);
}

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

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