//******************************************************************************************
// Program:  datechek.js - Contains high level and utility javascript functions for
//				checking form fields of specific types.  Mostly copied from sample code
//				found at Netscape site.
//			MDS 02/27/00
//
//			MDS 03/06/00 - set minimum year to 1901 because SQL Server not liking very old
//				dates
//
//			MDS 04/05/00 - commented out the parseint because for some reason it was returning
//  			a zero value when used to parse the string "09"
//
//			MDS 08/15/00 - allow dollar sign as input, when checking currency.
//
//			MDS 02/22/01 - add function isAlphanumeric.
//  			
//******************************************************************************************
//
//******************************************************************************************
// General Variable Declarations
//******************************************************************************************

// whitespace characters
var whitespace = " \t\n\r";

// 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;

var defaultEmptyOK = false

var digits = "0123456789";

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;

// BOI, followed by one or more lower or uppercase English letters
// or digits, followed by EOI.
var reAlphanumeric = /^[a-zA-Z0-9]+$/

//******************************************************************************************
// Functions to be called externally from forms being checked.
//******************************************************************************************


function checkSSN (chkssn) { 
	var normalizedSSN = stripCharsInBag(chkssn.value, "- ");
    if (!isSSN(normalizedSSN)) {
    	alert ("Please enter a valid SSN in the form of 123-45-6789");
		return false;
    } else {
    	// if you don't want to reformats as 123-456-7890, comment next line out
        chkssn.value = reformatSSN(normalizedSSN)
        return true;
    }
}

function checkdate(chkdate) {
	var sep = ""
	datestring = new String(chkdate.value);
	if (datestring.search("/") != -1) sep = "/";
	if (datestring.search("-") != -1) sep = "-";

	if (sep == "") {
		alert ("Date should be in the form of MM/DD/CCYY or MM-DD-CCYY");
		return false;
	}
		
// Split date up into the parts MM, DD, CCYY
	dateparts = datestring.split(sep);
	if (!(isDate(dateparts[2], dateparts[0], dateparts[1]))) {
		alert ("Please enter a valid date in the form of MM-DD-CCYY");
		return false;
	}
return true;
}

function checkphone(phone) {
	var sep = ""
	var testphone = ""
	phonestring = new String(phone.value);
	if (phonestring.search("-") != -1) sep = "-";

	if (sep == "") {
		alert ("Phone number should be in the form of 111-222-3333");
		return false;
	}
		
// Split phone up into the parts 111, 222, 3333
	phoneparts = phonestring.split(sep);
	testphone = phoneparts[0] + phoneparts[1] + phoneparts[2];
	if(!isUSPhoneNumber(testphone)) {	
		alert("Phone number should be in the form of 111-222-3333.");
		return false;
	}
	return true;
}

function datetocymd(chkdate) {
	var sep = ""
	var returndate = "";
	
	datestring = new String(chkdate.value);
	if (datestring.search("/") != -1) sep = "/";
	if (datestring.search("-") != -1) sep = "-";

	if (sep == "") {
		alert ("Date should be in the form of MM/DD/CCYY or MM-DD-CCYY");
		return false;
	}
		
// Split date up into the parts MM, DD, CCYY
	dateparts = datestring.split(sep);

	returndate = returndate.concat(dateparts[2],sep,dateparts[0],sep,dateparts[1]);	
	return (returndate);
}

// isEmail (STRING s [, BOOLEAN emptyOK])
// 
// Email address must be of form a@b.c -- in other words:
// * there must be at least one character before the @
// * there must be at least one character before and after the .
// * the characters @ and . are both required
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

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;
    
    // there must be >= 1 character before @, so we
    // start looking at character position 1 
    // (i.e. second character)
    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 Currencystripped (chkcur) { 
	var strippedcur = stripCharsInBag(chkcur.value, ".,$ ");
    if (!isInteger(strippedcur)) {
    	alert ("Please enter a valid amount in the form of 1,234.56");
		return false;
    } else {
        chkcur.value = stripCharsInBag(chkcur.value, ",$ ");	// Leave decimal
        return true;
    }
}

//******************************************************************************************
// Utility Functions.  These can be called externally from forms being checked, but will
// generally be called by other higher level functions herein.
//******************************************************************************************



// 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;
}

// isUSPhoneNumber (STRING s [, BOOLEAN emptyOK])
// 
// isUSPhoneNumber returns true if string s is a valid U.S. Phone
// Number.  Must be 10 digits.
//
// NOTE: Strip out any delimiters (spaces, hyphens, parentheses, etc.)
// from string s before calling this function.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

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)
}

// 
// isSSN returns true if string s is a valid U.S. Social
// Security Number.  Must be 9 digits.
//
// NOTE: Strip out any delimiters (spaces, hyphens, etc.)
// from string s before calling this function.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

function isSSN (s) {   
	return (isInteger(s) && s.length == 9)
}

// takes SSN, a string of 9 digits
// and reformats as 123-45-6789

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

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;
}

// 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;
}

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
}
// isDate (STRING year, STRING month, STRING day)
//
// isDate returns true if string arguments year, month, and day 
// form a valid date.
// 

function isDate (year, month, day)
{   // catch invalid years (not 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;
}

// isYear (STRING s [, BOOLEAN emptyOK])
// 
// isYear returns true if string s is a valid 
// Year number.  Must be 4 digits only.
// 
//
// And yes, this function is not Year 10000 compliant, but 
// because I am giving you 8003 years of advance notice,
// I don't feel very guilty about this ...
//
// For B.C. compliance, write your own function. ;->
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

function isYear (s) {
var minyear = 1900
    if (isEmpty(s)) 
       if (isYear.arguments.length == 1) return defaultEmptyOK;
       else return (isYear.arguments[1] == true);
    if (!isNonnegativeInteger(s)) return false;
	if (s <= minyear) return false;
    return ((s.length == 4));
}

// isDay (STRING s [, BOOLEAN emptyOK])
// 
// isDay returns true if string s is a valid 
// day number between 1 and 31.
// 
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

function isDay (s)
{   if (isEmpty(s)) 
       if (isDay.arguments.length == 1) return defaultEmptyOK;
       else return (isDay.arguments[1] == true);   
    if (!isIntegerInRange (s, 1, 31)) return false;
    return ((s.length == 2));
}

// isMonth (STRING s [, BOOLEAN emptyOK])
// 
// isMonth returns true if string s is a valid 
// month number between 1 and 12.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

function isMonth (s)
{   if (isEmpty(s)) 
       if (isMonth.arguments.length == 1) return defaultEmptyOK;
       else return (isMonth.arguments[1] == true);
    if (!isIntegerInRange (s, 1, 12)) return false;
    return ((s.length == 2));
}

// daysInFebruary (INTEGER year)
// 
// Given integer argument year,
// returns number of days in February of that year.

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 );
}

// Check whether string s is empty.

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

// 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).

//  MDS commented out the parseint because for some reason it was returning
//  a zero value when used to parse the string "09"

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

// 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))
    }
}

// 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;
}

// Returns true if character c is a digit 
// (0 .. 9).

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

// isAlphanumeric (STRING s [, BOOLEAN emptyOK])
// 
// Returns true if string s is English letters 
// (A .. Z, a..z) and numbers only.
function isAlphanumeric (s) {   
	var i;
    return reAlphanumeric.test(s)
}