// VARIABLE DECLARATIONS

var digits = "0123456789";

var lowercaseLetters = "abcdefghijklmnopqrstuvwxyz"

var uppercaseLetters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"


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


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

// m is an abbreviation for "missing"

var mPrefix = "Please select/enter "
var mSuffix = " "

// s is an abbreviation for "string"

var semail_format = "your prefered email format"
var svchFirstName = "your first name"
var svchLastName = "your last name"
var svchCustomerType = "if you are a returning customer"
var svchCallTime = "your prefered time to be called"
var sz_vchPhone = "your telephone number"
var schSubscribe = "if you would like to receive our newsletter"
var svchState = "your state of residence"



// i is an abbreviation for "invalid"

var iEmail = "This is not a valid email address (eg. a.smith@somewhere.com). Please re-enter your email address."


// p is an abbreviation for "prompt"

var pEntryPrompt = "Please enter a "


// 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
}




// 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;
}


// WORKAROUND FUNCTION FOR NAVIGATOR 2.0.2 COMPATIBILITY.
//
// The below function *should* be unnecessary.  In general,
// avoid using it.  Use the standard method indexOf instead.
//
// However, because of an apparent bug in indexOf on 
// Navigator 2.0.2, the below loop does not work as the
// body of stripInitialWhitespace:
//
// while ((i < s.length) && (whitespace.indexOf(s.charAt(i)) != -1))
//   i++;
//
// ... so we provide this workaround function charInString
// instead.
//
// charInString (CHARACTER c, STRING s)
//
// Returns true if single character c (actually a string)
// is contained within string s.

function charInString (c, s)
{   for (i = 0; i < s.length; i++)
    {   if (s.charAt(i) == c) return true;
    }
    return false
}


// 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;
}



/* 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)
{   alert(mPrefix + s + mSuffix)
    theField.focus()
    return false
}

function warnEmptyRadio (theField, s)
{ 
    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 == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    if (isWhitespace(theField.value)) 
       return warnEmpty (theField, s);
    else return true;
}

function checkDropDown (theField, s, emptyOK)
{   // Next line is needed on NN3 to avoid "undefined is not a number" error
    // in equality comparison below.
  //  if (checkDropDown.arguments.length == 2) emptyOK = defaultEmptyOK;
  //  if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    if (theField.value == "") 
       return warnEmpty (theField, s);
    else return true;
}


// checkStateCode (TEXTFIELD theField [, BOOLEAN emptyOK==false])
//
// Check that string theField.value is a valid U.S. state code.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

function checkStateCode (theField, emptyOK)
{   if (checkStateCode.arguments.length == 1) emptyOK = defaultEmptyOK;
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;
    else
    {  theField.value = theField.value.toUpperCase();
       if (!isStateCode(theField.value, false)) 
          return warnInvalid (theField, iStateCode);
       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;
}

// Get checked value from radio button.

function getRadioButtonValue (radio, s)
{   for (var i = 0; i < radio.length; i++)
    {
	var checkvalue=radio[i].checked;
	if (checkvalue) { break }
    }
	if (!(checkvalue)) {
		checkvalue =""
		return checkvalue
	}
    	return checkvalue 
}




function checkRadio (theField, s, emptyOK)
{   var cardType = getRadioButtonValue (theField)
    if (!cardType)
       return warnEmptyRadio (theField, s);
    else return true;
}