// Set of JavaScript functions for validating input on
// an HTML form.  These are the includes that are called
// from the actual validation functions:
//
// SUPPORTING VALIDATION FUNCTIONS ARE PROVIDED IN:
//      FormCheckFunctions.js
//
// These utility functions validate that:
//  - characters are Letter, Digit, or LetterOrDigit
//  - strings are a Signed, Positive, Negative, Nonpositive, or
//    Nonnegative integer
//  - strings are a Float or a SignedFloat
//  - strings are Alphabetic, Alphanumeric, or Whitespace
//  - strings contain an integer within a specified range
//
// Other utility functions are provided to:
// 	- remove from a string characters which are/are not
//	  in a "bag" of selected characters
// 	- reformat a string, adding delimiter characters
//	- strip whitespace/leading whitespace from a string
//  - reformat U.S. phone numbers, ZIP codes, SSN
//
// Many of the below functions take an optional parameter eok (for "emptyOK")
// which determines whether the empty string will return true or false.
// Default behavior is controlled by global variable defaultEmptyOK.
//
// 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.
// isIntegerInRange (s, a, b [,eok])   True if string s is an integer between a and b, inclusive.
//
// 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.

// ORIGINAL:
// 18 Feb 97 created Eric Krock
// (c) 1997 Netscape Communications Corporation
//
// MODIFIED FROM ORIGINAL
// 15 Jul 2001 Craig Meese
// visionbox
// =================================================================================================
// =================================================================================================

// VARIABLE DECLARATIONS
var digits = "0123456789";
var lowercaseLetters = "abcdefghijklmnopqrstuvwxyz";
var uppercaseLetters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
// whitespace characters
var whitespace = " \t\n\r";
// US 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;
// characters which are allowed in international phone numbers (a leading + is OK)
var validWorldPhoneChars = 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
// Social Security Numbers
var SSNDelimiters = "- ";
// characters which are allowed in Social Security Numbers
var validSSNChars = digits + SSNDelimiters;
// U.S. Social Security Numbers have 9 digits. They are formatted as 123-45-6789.
var digitsInSocialSecurityNumber = 9;
// non-digit characters which are allowed in US ZIP Codes
var ZIPCodeDelimiters = "-";
// 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 = " ";

// 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;

// Attempting to make this library run on Navigator 2.0,
// so I'm supplying this array creation routine as per
// JavaScript 1.0 documentation.  If you're using
// Navigator 3.0 or later, you don't need to do this;
// you can use the Array constructor instead.
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;
}

// Valid U.S. Postal Codes for states, territories, armed forces, etc.
// See http://www.usps.gov/ncsc/lookups/abbr_state.txt.
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))
}

// 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)
}

// 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).
// 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.
// 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];
    // What the next line 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];
    // What the next line 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];
    // What the next line 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];
    // What the next line 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.
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.
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.
// 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 (0..9) only.
// 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.
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));
}