function preloadImages() { //v1.2
		if (document.images) {
			var imgFiles = preloadImages.arguments;
			var preloadArray = new Array();
			for (var i=0; i<imgFiles.length; i++) {
				preloadArray[i] = new Image;
				preloadArray[i].src = imgFiles[i];
			}
		}
	preload = "ready";
	}

	function swapImage() { //v1.2
		var i,j=0,objStr,obj,swapArray=new Array,oldArray=document.swapImgData;
		for (i=0; i < (swapImage.arguments.length-2); i+=3) {
			objStr = swapImage.arguments[(navigator.appName == 'Netscape')?i:i+1];
			if ((objStr.indexOf('document.layers[')==0 && document.layers==null) ||
					(objStr.indexOf('document.all[')	 ==0 && document.all	 ==null))
				objStr = 'document'+objStr.substring(objStr.lastIndexOf('.'),objStr.length);
			obj = eval(objStr);
			if (obj != null && (preload == "ready")) {
				swapArray[j++] = obj;
				swapArray[j++] = (oldArray==null || oldArray[j-1]!=obj)?obj.src:oldArray[j];
				obj.src = swapImage.arguments[i+2];
		} }
		document.swapImgData = swapArray; //used for restore
	}

	function swapImgRestore() { //v1.2
		if (document.swapImgData != null && (preload == "ready"))
			for (var i=0; i<(document.swapImgData.length-1); i+=2)
				document.swapImgData[i].src = document.swapImgData[i+1];
	}

	function displayStatusMsg(msgStr) { //v1.2
		status=msgStr;
		document.returnValue = true;
	}
	//-->

function validateDetails(form)
{   return (
	checkString(form.elements["LastName"],sLastName) &&

	checkString(form.elements["StreetPO"],sStreetPO) &&
	checkString(form.elements["Zip"],sZip) &&
	checkString(form.elements["City"],sCity) &&
	checkString(form.elements["Country"],sCountry) &&
	checkInternationalPhone(form.elements["PhoneNr"]) &&
	checkInternationalFax(form.elements["FaxNr"], true) &&
	checkEmail(form.elements["EmailAddress"])
	 &&
		checkCreditCard (form.elements["CreditCardType"], form.elements["CreditCardNumber"]) &&
		checkYear(form.elements["ExpirationYear"]) &&
		checkMonth(form.elements["ExpirationMonth"])

    )
}

// VARIABLE DECLARATIONS

var digits = "0123456789";
var lowercaseLetters = "abcdefghijklmnopqrstuvwxyz"
var uppercaseLetters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
// whitespace characters
var whitespace = " \t\n\r";
// non-digit characters which are allowed in phone numbers
var phoneNumberDelimiters = "()- ";
// characters which are allowed in international phone numbers
// (a leading + is OK)
var validWorldPhoneChars = digits + phoneNumberDelimiters + "+";
// non-digit characters which are allowed in credit card numbers
var creditCardDelimiters = " -."

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

// m is an abbreviation for "missing"
var mPrefix = "U heeft niets ingevuld bij '"
var mSuffix = "'. Dit veld is verplicht. U kunt het nu invullen."

// s is an abbreviation for "string"
var sLastName = "Achternaam"
var sCompanyName = "Bedrijfsnaam"
var sStreetPO = "Straat / Postbus"
var sZip = "Postcode"
var sCity = "Plaats"
var sCountry = "Land"
var sExpirationDate = "Expiration Date"

// i is an abbreviation for "invalid"
var iWorldPhone = "Dit veld bevat geen geldig telefoonnummer. U kunt het nu opnieuw invullen."
var iWorldFax = "Dit veld bevat geen geldig faxnummer. U kunt het nu opnieuw invullen."
var iEmail = "Dit veld bevat geen geldig e-mail adres. U kunt het nu opnieuw invullen."
var iCreditCardPrefix = "Dit is geen geldig "
var iCreditCardSuffix = " credit card nummer. U kunt het nu opnieuw invullen."
var iDay = "Dit veld moet een dagnummer tussen de 1 en de 31 zijn. U kunt het nu opnieuw invullen."
var iMonth = "Dit veld moet een maandnummer tussen de 1 en de 12 zijn. U kunt het nu opnieuw invullen."
var iYear = "Dit veld moet een 2 of 4 cijferig jaarnummer zijn. U kunt het nu opnieuw invullen."
var iDatePrefix = "The Day, Month, and Year for "
var iDateSuffix = " do not form a valid date.  Please reenter them now."

// p is an abbreviation for "prompt"
var pEntryPrompt = "Please enter a "
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) {
//*** 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
}

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;

// 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;
}

// 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) ) );
}

// isInternationalPhoneNumber (STRING s [, BOOLEAN emptyOK])
//
// isInternationalPhoneNumber returns true if string s is a valid
// international phone number.  Must be digits only; any length OK.
// May be prefixed by + character.
//
// NOTE: A phone number of all zeros would not be accepted.
// I don't think that is a valid phone number anyway.
//
// NOTE: Strip out any delimiters (spaces, hyphens, parentheses, etc.)
// from string s before calling this function.  You may leave in
// leading + character if you wish.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function isInternationalPhoneNumber (s)
{   if (isEmpty(s))
       if (isInternationalPhoneNumber.arguments.length == 1) return defaultEmptyOK;
       else return (isInternationalPhoneNumber.arguments[1] == true);
    return (isPositiveInteger(s))
}

// 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;
}

// isYear (STRING s [, BOOLEAN emptyOK])
//
// isYear returns true if string s is a valid
// Year number.  Must be 2 or 4 digits only.
//
// For Year 2000 compliance, you are advised
// to use 4-digit year numbers everywhere.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function isYear (s)
{   if (isEmpty(s))
       if (isYear.arguments.length == 1) return defaultEmptyOK;
       else return (isYear.arguments[1] == true);
    if (!isNonnegativeInteger(s)) return false;
    return ((s.length == 2) || (s.length == 4));
}

// 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));
}

// 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);
    return isIntegerInRange (s, 1, 12);
}

// 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);
    return isIntegerInRange (s, 1, 31);
}

// 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 );
}

// 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 2- or 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;
}
/* FUNCTIONS TO NOTIFY USER OF INPUT REQUIREMENTS OR MISTAKES. */
// Display prompt string s in status bar.
function prompt (s)
{   window.status = s
}

// Display data entry prompt string s in status bar.
function promptEntry (s)
{   window.status = pEntryPrompt + s
}

// Notify user that required field theField is empty.
// String s describes expected contents of theField.value.
// Put focus in theField and return false.
function warnEmpty (theField, s)
{   theField.focus()
    alert(mPrefix + s + mSuffix)
    return false
}

// 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
}
/* FUNCTIONS TO INTERACTIVELY CHECK VARIOUS FIELDS. */
// checkString (TEXTFIELD theField, STRING s, [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is not all whitespace.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function checkString (theField, s, emptyOK)
{   // Next line is needed on NN3 to avoid "undefined is not a number" error
    // in equality comparison below.
    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;
}

// checkInternationalPhone (TEXTFIELD theField [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is a valid International Phone.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function checkInternationalPhone (theField, emptyOK)
{   if (checkInternationalPhone.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else
    {  var normalizedPhone = stripCharsInBag(theField.value, phoneNumberDelimiters + "+")
       if (!isInternationalPhoneNumber(normalizedPhone, false))
          return warnInvalid (theField, iWorldPhone);
	   else return true;
    }
}

// checkInternationalFax (TEXTFIELD theField [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is a valid International Phone.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function checkInternationalFax (theField, emptyOK)
{   if (checkInternationalFax.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else
    {  var normalizedPhone = stripCharsInBag(theField.value, phoneNumberDelimiters + "+")
       if (!isInternationalPhoneNumber(normalizedPhone, false))
          return warnInvalid (theField, iWorldFax);
	   else return true;
    }
}

// checkEmail (TEXTFIELD theField [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is a valid Email.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
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;
}

// Check that string theField.value is a valid Year.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

function checkYear (theField, emptyOK)
{   if (checkYear.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    if (!isYear(theField.value, false))
       return warnInvalid (theField, iYear);
    else return true;
}


// Check that string theField.value is a valid Month.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

function checkMonth (theField, emptyOK)
{   if (checkMonth.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    if (!isMonth(theField.value, false))
       return warnInvalid (theField, iMonth);
    else return true;
}


// Check that string theField.value is a valid Day.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

function checkDay (theField, emptyOK)
{   if (checkDay.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    if (!isDay(theField.value, false))
       return warnInvalid (theField, iDay);
    else return true;
}



// checkDate (yearField, monthField, dayField, STRING labelString [, OKtoOmitDay==false])
//
// Check that yearField.value, monthField.value, and dayField.value
// form a valid date.
//
// If they don't, labelString (the name of the date, like "Birth Date")
// is displayed to tell the user which date field is invalid.
//
// If it is OK for the day field to be empty, set optional argument
// OKtoOmitDay to true.  It defaults to false.

function checkDate (yearField, monthField, dayField, labelString, OKtoOmitDay)
{   // Next line is needed on NN3 to avoid "undefined is not a number" error
    // in equality comparison below.
    if (checkDate.arguments.length == 4) OKtoOmitDay = false;
    if (!isYear(yearField.value)) return warnInvalid (yearField, iYear);
    if (!isMonth(monthField.value)) return warnInvalid (monthField, iMonth);
    if ( (OKtoOmitDay == true) && isEmpty(dayField.value) ) return true;
    else if (!isDay(dayField.value))
       return warnInvalid (dayField, iDay);
    if (isDate (yearField.value, monthField.value, dayField.value))
       return true;
    alert (iDatePrefix + labelString + iDateSuffix)
    return false
}



// 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
}