//
// SUMMARY
//
// This is a set of JavaScript functions for validating input on an HTML form.
//
// BASIC DATA VALIDATION FUNCTIONS:
//
// isValidCreditCard(cardno)           Checks the card number for a valid Credit Card.
// isWhitespace (s)                    Check whether string s is empty or whitespace.
// isValidEmailAddress(s)              Checks if the email address is valid.
// isIPAddress(s)                      Checks whether the string is a valid IP Address.
// 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.
// isIntegerInRange (s, a, b [,eok])   True if string s is an integer between a and b, inclusive.

// Regular Expression Declarations
var ipAddressRegExp = /^((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])\.){3}(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])$/;
var emailAddressRegExp = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;

// VARIABLE DECLARATIONS
var digits = "0123456789";
var decimalPointDelimiter = ".";
var whitespace = " \t\n\r";

// CONSTANT STRING DECLARATIONS
// (grouped for ease of translation and localization)

// Global variable defaultEmptyOK defines default return value
// for many functions when they are passed the empty string.
// By default, they will return defaultEmptyOK.
//
// defaultEmptyOK is false, which means that by default,
// these functions will do "strict" validation.  Function
// isInteger, for example, will only return true if it is
// passed a string containing an integer; if it is passed
// the empty string, it will return false.
//
// You can change this default behavior globally (for all
// functions which use defaultEmptyOK) by changing the value
// of defaultEmptyOK.
//
// Most of these functions have an optional argument emptyOK
// which allows you to override the default behavior for
// the duration of a function call.
//
// This functionality is useful because it is possible to
// say "if the user puts anything in this field, it must
// be an integer (or a phone number, or a string, etc.),
// but it's OK to leave the field empty too."
// This is the case for fields which are optional but which
// must have a certain kind of content if filled in.

var defaultEmptyOK = false;

// Validate the credit card number
function isValidCreditCard(card) {
  var val, i, tmp, digits = 0, check_sum = 0;
  var num;
  var weight = 1;
  var cnum = new Array();

  // this will parse out all non-digit chars.
  for (i=0; i<card.length; i++) {
    num = card.charAt(i);
    if (num>='0' && num<='9') {
      cnum[digits] = num; //Integer.parseInt(card.substring(i,i+1));
      digits++;
    }
  }

  // this varifys that the numbers are MOD 10
  for (i=digits-1; i>=0; i--) {
    val = (cnum[i] * weight);
    if (val>9) val -= 9;
    check_sum += val;
    weight = (weight == 1) ? 2 : 1;
  }
  // returns true or false depending on the card number.
  var result = (((check_sum % 10) == 0) ? true: false);
  //if (!result) alert("Credit Card number is invalid.");

  return (result);
}

// Validates an IP Address is in the correct format.
function isIPAddress(value) {
	if (window.RegExp) {
		var ipAddress = value.replace(".","");
		if (isInteger.ipAddress) {
			return true;
		}
	}  else {
		if (ipAddressRegExp.test(value)) {
			return true;
		}
	}
	
	return false;
}

// Validates an e-mail address is in the correct format.
function isValidEmailAddress(str) {
  if (window.RegExp) {
	  if (emailAddressRegExp.test(str)) {
      return true;
    }
    return false;
  } else {
    return ( str.indexOf("@") >= 0 );
  }
}

// Defines a trim function for strings.
// Usage: string.trim(); 
String.prototype.trim = function() {
	return this.replace(/^\s+|\s+$/g,"");
}

// Trims whitspace from a string.
function trim(stringValue) {
	return stringValue.replace(/^\s+|\s+$/g,"");
}

// Trims whitespace from the left side of a string.
function ltrim(stringToTrim) {
	return stringToTrim.replace(/^\s+/,"");
}

// Trims whitespace from the right side of a string.
function rtrim(stringToTrim) {
	return stringToTrim.replace(/\s+$/,"");
}

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

// Returns true if string  is empty or whitespace characters only.
function isWhitespace (stringValue){
	return isEmpty(trim(stringValue));
}



// 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);
}

// Returns true if character c is an English letter
// (A .. Z, a..z).
//
// NOTE: Need i18n version to support European characters.
// This could be tricky due to different character
// sets and orderings for various languages and platforms.

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.
//
// Accepts non-signed integers only. Does not accept floating
// point, exponential notation, etc.
//
// We don't use parseInt because that would accept a string
// with trailing non-numeric characters.
//
// By default, returns defaultEmptyOK if s is empty.
// There is an optional second argument called emptyOK.
// emptyOK is used to override for a single function call
//      the default behavior which is specified globally by
//      defaultEmptyOK.
// If emptyOK is false (or any value other than true),
//      the function will return false if s is empty.
// If emptyOK is true, the function will return true if s is empty.
//
// 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.
//
// Does not accept floating point, exponential notation, etc.
//
// We don't use parseInt because that would accept a string
// with trailing non-numeric characters.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
//
// 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.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

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.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

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.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

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.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

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.
//
// Also returns true for unsigned integers. If you wish
// to distinguish between integers and floating point numbers,
// first call isInteger, then call isFloat.
//
// Does not accept exponential notation.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

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 -.
//
// Also returns true for unsigned integers. If you wish
// to distinguish between integers and floating point numbers,
// first call isSignedInteger, then call isSignedFloat.
//
// Does not accept exponential notation.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

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.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
//
// NOTE: Need i18n version to support European characters.
// This could be tricky due to different character
// sets and orderings for various languages and platforms.
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;
}

// isAlphanumeric (STRING s [, BOOLEAN emptyOK])
//
// Returns true if string s is English letters
// (A .. Z, a..z) and numbers only.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
//
// NOTE: Need i18n version to support European characters.
// This could be tricky due to different character
// sets and orderings for various languages and platforms.

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;
}

// reformat (TARGETSTRING, STRING, INTEGER, STRING, INTEGER ... )
//
// Handy function for arbitrarily inserting formatting characters
// or delimiters of various kinds within TARGETSTRING.
//
// reformat takes one named argument, a string s, and any number
// of other arguments.  The other arguments must be integers or
// strings.  These other arguments specify how string s is to be
// reformatted and how and where other strings are to be inserted
// into it.
//
// reformat processes the other arguments in order one by one.
// * If the argument is an integer, reformat appends that number
//   of sequential characters from s to the resultString.
// * If the argument is a string, reformat appends the string
//   to the resultString.
//
// NOTE: The first argument after TARGETSTRING must be a string.
// (It can be empty.)  The second argument must be an integer.
// Thereafter, integers and strings must alternate.  This is to
// provide backward compatibility to Navigator 2.0.2 JavaScript
// by avoiding use of the typeof operator.
//
// It is the caller's responsibility to make sure that we do not
// try to copy more characters from s than s.length.
//
// 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)
//
// HINT:
//
// If you have a string which is already delimited in one way
// (example: a phone number delimited with spaces as "123 456 7890")
// and you want to delimit it in another way using function reformat,
// call function stripCharsNotInBag to remove the unwanted
// characters, THEN call function reformat to delimit as desired.
//
// 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;
}


// 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.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
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));
}

// 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)
{   theField.focus();
    theField.select();
    alert(s);
    return false;
}

function validatePostalCode(field, country) {
    var valid = "0123456789-";
    var hyphencount = 0;
    if (country == null) {
        country = "US";
    }

    if (country == "US") {

        if (field.length!=5 && field.length!=10) {
          //alert("Please enter your 5 digit or 5 digit+4 zip code.");
          return false;
        }
        for (var i=0; i < field.length; i++) {
          temp = "" + field.substring(i, i+1);
          if (temp == "-") hyphencount++;
          if (valid.indexOf(temp) == "-1") {
            return false;
          }
          if ((hyphencount > 1) || ((field.length==10) && ""+field.charAt(5)!="-")) {
            return false;
          }
        }
        return true;
    } else if (country == "CA") {

        if (field.length!=7) {
          return false;
        }

        for (var i=0; i < field.length; i++) {

            var validchar = false;
            var charValue = field.substring(i, i+1);

            switch (i) {
               case 0: validchar = isLetter(charValue); break;
               case 1: validchar = isDigit(charValue); break;
               case 2: validchar = isLetter(charValue); break;
               case 3: validchar = charValue == " "; break;
               case 4: validchar = isDigit(charValue); break;
               case 5: validchar = isLetter(charValue); break;
               case 6: validchar = isDigit(charValue); break;
               default: validchar = false;
            }

            if (validchar == false) {
                break;
            }
        }
        return validchar;

    }


  }