// ----------------------------------------------------------------------
// Javascript form validation routines.
// Author: Stephen Poley
//
// Simple routines to quickly pick up obvious typos.
// All validation routines return true if executed by an older browser:
// in this case validation must be left to the server.
//
// Update Jun 2005: discovered that reason IE wasn't setting focus was
// due to an IE timing bug. Added 0.1 sec delay to fix.
//
// Update Oct 2005: minor tidy-up: unused parameter removed
//
// Update Jun 2006: minor improvements to variable names and layout
// ----------------------------------------------------------------------

var nbsp = 160;		// non-breaking space char
var node_text = 3;	// DOM text node-type
var emptyString = /^\s*$/ ;
var global_valfield;	// retain valfield for timer thread

// --------------------------------------------
//                  trim
// Trim leading/trailing whitespace off string
// --------------------------------------------

function trim(str)
{
  return str.replace(/^\s+|\s+$/g, '');
}


// --------------------------------------------
//                  setfocus
// Delayed focus setting to get around IE bug
// --------------------------------------------

function setFocusDelayed()
{
  global_valfield.focus();
}

function setfocus(valfield)
{
  // save valfield in global variable so value retained when routine exits
  global_valfield = valfield;
  setTimeout( 'setFocusDelayed()', 100 );
}


// --------------------------------------------
//                  msg
// Display warn/error message in HTML element.
// commonCheck routine must have previously been called
// --------------------------------------------

function msg(fld,     // id of element to display message in
             msgtype, // class to give element ("warn" or "error")
             message) // string to display
{
  // setting an empty string can give problems if later set to a 
  // non-empty string, so ensure a space present. (For Mozilla and Opera one could 
  // simply use a space, but IE demands something more, like a non-breaking space.)
  var dispmessage;
  if (emptyString.test(message)) 
    dispmessage = String.fromCharCode(nbsp);    
  else  
    dispmessage = message;

  var elem = document.getElementById(fld);
  elem.firstChild.nodeValue = dispmessage;  
  
  elem.className = msgtype;   // set the CSS class to adjust appearance of message
}

// --------------------------------------------
//            commonCheck
// Common code for all validation routines to:
// (a) check for older / less-equipped browsers
// (b) check if empty fields are required
// Returns true (validation passed), 
//         false (validation failed) or 
//         proceed (don't know yet)
// --------------------------------------------

var proceed = 2;  

function commonCheck    (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required)   // true if required
{
	msg (infofield, "warn", "");   // clear the message area
  	if (!document.getElementById) {	return true; } // not available on this browser - leave validation to the server
  	var elem = document.getElementById(infofield);
  	if (!elem.firstChild) { return true; } // not available on this browser 
  	if (elem.firstChild.nodeType != node_text) { return true; } // infofield is wrong type of node  
  	if (valfield[0] != null && valfield.type != 'select-one') { // Handle radio buttons
  		if (valfield[0].type == 'radio') {
			var length = valfield.length;
			var isChecked = false;
			for (i = 0; i < length; i++) {
				if (valfield[i].checked == true) {
					isChecked = true;
				}
			}
			if (required && !isChecked) {
				msg (infofield, "error", "This is a required field");  
				setfocus(valfield[0]);
	      		return false;
			} else {
				msg (infofield, "warn", "");   // OK
		      	return true;  
			}
		} else if (valfield[0].type == 'checkbox') {
			var length = valfield.length;
			var isChecked = false;
			for (i = 0; i < length; i++) {
				if (valfield[i].checked == true) {
					isChecked = true;
				}
			}
			if (required && !isChecked) {
				msg (infofield, "error", "This is a required field");  
				setfocus(valfield[0]);
	      		return false;
			} else {
				msg (infofield, "warn", "");   // OK
		      	return true;  
			}
		}
	} else if (valfield.type == 'checkbox') {
		if (required && !valfield.checked) {
			msg (infofield, "error", "This is a required field");  
			setfocus(valfield);
      		return false;
		} else {
			msg (infofield, "warn", "");   // OK
	      	return true;  
		}
	} else if (emptyString.test(valfield.value)) {
    	if (required) {
      		msg (infofield, "error", "This is a required field");  
      		setfocus(valfield);
      		return false;
    	} else {
	      	msg (infofield, "warn", "");   // OK
	      	return true;  
    	}
  	}
  	return proceed;
}

// --------------------------------------------
//            validatePresent
// Validate if something has been entered
// Returns true if so 
// --------------------------------------------

function validatePresent(valfield,   // element to be validated
                         infofield) // id of element to receive info/error msg
         
{
  var stat = commonCheck (valfield, infofield, true);
  if (stat != proceed) return stat;

  msg (infofield, "warn", "");  
  return true;
}

// --------------------------------------------
//               validateEmail
// Validate if e-mail address
// Returns true if so (and also if could not be executed because of old browser)
// --------------------------------------------

function validateEmail  (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required)   // true if required
{
  var stat = commonCheck (valfield, infofield, required);
  if (stat != proceed) return stat;

  var tfld = trim(valfield.value);  // value of field with whitespace trimmed off
  var email = /^[^@]+@[^@.]+\.[^@]*\w\w$/  ;
  if (!email.test(tfld)) {
    msg (infofield, "error", "ERROR: not a valid e-mail address");
    setfocus(valfield);
    return false;
  }

  var email2 = /^[A-Za-z][\w.-]+@\w[\w.-]+\.[\w.-]*[A-Za-z][A-Za-z]$/  ;
  if (!email2.test(tfld)) 
    msg (infofield, "warn", "Unusual e-mail address - check if correct");
  else
    msg (infofield, "warn", "");
  return true;
}


// --------------------------------------------
//            validateTelnr
// Validate telephone number
// Returns true if so (and also if could not be executed because of old browser)
// Permits spaces, hyphens, brackets and leading +
// --------------------------------------------

function validateTelnr  (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required)   // true if required
{
  var stat = commonCheck (valfield, infofield, required);
  if (stat != proceed) return stat;

  var tfld = trim(valfield.value);  // value of field with whitespace trimmed off
  var telnr = /^\+?[0-9 ()-]+[0-9]$/  ;
  if (!telnr.test(tfld)) {
    msg (infofield, "error", "ERROR: not a valid telephone number. Characters permitted are digits, space ()- and leading +");
    setfocus(valfield);
    return false;
  }

  var numdigits = 0;
  for (var j=0; j<tfld.length; j++)
    if (tfld.charAt(j)>='0' && tfld.charAt(j)<='9') numdigits++;

  if (numdigits<6) {
    msg (infofield, "error", "ERROR: " + numdigits + " digits - too short");
    setfocus(valfield);
    return false;
  }

  if (numdigits>14)
    msg (infofield, "warn", numdigits + " digits - check if correct");
  else { 
    if (numdigits<10)
      msg (infofield, "warn", "Only " + numdigits + " digits - check if correct");
    else
      msg (infofield, "warn", "");
  }
  return true;
}

// --------------------------------------------
//             validateAge
// Validate person's age
// Returns true if OK 
// --------------------------------------------

function validateAge    (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required)   // true if required
{
  var stat = commonCheck (valfield, infofield, required);
  if (stat != proceed) return stat;

  var tfld = trim(valfield.value);
  var ageRE = /^[0-9]{1,3}$/
  if (!ageRE.test(tfld)) {
    msg (infofield, "error", "ERROR: not a valid age");
    setfocus(valfield);
    return false;
  }

  if (tfld>=200) {
    msg (infofield, "error", "ERROR: not a valid age");
    setfocus(valfield);
    return false;
  }

  if (tfld>110) msg (infofield, "warn", "Older than 110: check correct");
  else {
    if (tfld<7) msg (infofield, "warn", "Bit young for this, aren't you?");
    else        msg (infofield, "warn", "");
  }
  return true;
}

// --------------------------------------------
//             validateAge
// Validate person's age
// Returns true if OK 
// --------------------------------------------

function validateNumber    (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required,	// true if required
                         message)   // custom message
{
  var stat = commonCheck (valfield, infofield, required);
  if (stat != proceed) return stat;

  var tfld = trim(valfield.value);
  var numberRE = /^[0-9]*$/
  if (!numberRE.test(tfld)) {
    msg (infofield, "error", message);
    setfocus(valfield);
    return false;
  }
  return true;
}

function validateDecimal    (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required,	// true if required
                         message)   // custom message
{
  var stat = commonCheck (valfield, infofield, required);
  if (stat != proceed) return stat;

  var tfld = trim(valfield.value);
  var decimalRE = /^\d{0,4}(\.\d{1,2})?$/
  if (!decimalRE.test(tfld)) {
    msg (infofield, "error", message);
    setfocus(valfield);
    return false;
  }
  return true;
}


function validateLength    (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         minlength,// minimum length
                         maxlength,	// maximum length
                         message)   // custom message
{
  var stat = commonCheck (valfield, infofield, true);
  if (stat != proceed) return stat;

  var tfld = trim(valfield.value);
  
  if (tfld.length > maxlength || tfld.length < minlength) {
    msg (infofield, "error", message);
    setfocus(valfield);
    return false;
  }
  return true;
}

function validatePostalCode    (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         message)   // custom message
{
  var stat = commonCheck (valfield, infofield, true);
  if (stat != proceed) return stat;

  var tfld = trim(valfield.value);
  
  var postalCodeRE = /(^\d{5}$)|(^\d{5}-\d{4}$)/
  if (!postalCodeRE.test(tfld)) {
  	msg (infofield, "error", message);
   	setfocus(valfield);
   	return false;
  }
 
  return true;
}


function validateCreditCard (cardBrandField,   // element to be validated
							cardNumberField,
                         infofield)  // custom message
{
	var stat = commonCheck (cardNumberField, infofield, true);
  	if (stat != proceed) return stat;
	  
	var stat = commonCheck (cardBrandField, infofield, true);
  	if (stat != proceed) return stat;
  
  	var cardNo = cardNumberField.value;
  	var cardType = cardBrandField.options[cardBrandField.selectedIndex].text;
 
	if (!checkCreditCard (cardNo, cardType)) {
		msg (infofield, "error", ccErrors[ccErrorNo]);
   		setfocus(cardNumberField);
   		return false;
	} 
  	return true;
}

// --------------------------------------------
//            checkPresent
// Checks if something has been entered
// Returns true if so 
// --------------------------------------------

function checkPresent(valfield, infofield)   // element to be validate     
{
	var stat = commonCheck (valfield, infofield, false);
	return !emptyString.test(trim(valfield.value));
	
}


function removeCharacters( strValue, strMatchPattern ) {
/************************************************
DESCRIPTION: Removes characters from a source string
  based upon matches of the supplied pattern.

PARAMETERS:
  strValue - source string containing number.

RETURNS: String modified with characters
  matching search pattern removed

USAGE:  strNoSpaces = removeCharacters( ' sfdf  dfd',
                                '\s*')
*************************************************/
 var objRegExp =  new RegExp(strMatchPattern, 'gi');

 //replace passed pattern matches with blanks
  return strValue.replace(objRegExp,'');
}

function clearInfoField(infofield) {
	msg (infofield, "warn", "");   // Clear
}







/*============================================================================*/

/*

This routine checks the credit card number. The following checks are made:

1. A number has been provided
2. The number is a right length for the card
3. The number has an appropriate prefix for the card
4. The number has a valid modulus 10 number check digit if required

If the validation fails an error is reported.

The structure of credit card formats was gleaned from a variety of sources on 
the web, although the best is probably on Wikepedia ("Credit card number"):

  http://en.wikipedia.org/wiki/Credit_card_number

Parameters:
            cardnumber           number on the card
            cardname             name of card as defined in the card list below

Author:     John Gardner
Date:       1st November 2003
Updated:    26th Feb. 2005      Additional cards added by request
Updated:    27th Nov. 2006      Additional cards added from Wikipedia

*/

/*
   If a credit card number is invalid, an error reason is loaded into the 
   global ccErrorNo variable. This can be be used to index into the global error  
   string array to report the reason to the user if required:
   
   e.g. if (!checkCreditCard (number, name) alert (ccErrors(ccErrorNo);
*/

var ccErrorNo = 0;
var ccErrors = new Array ();

ccErrors [0] = "Unknown card type";
ccErrors [1] = "No card number provided";
ccErrors [2] = "Credit card number is in invalid format";
ccErrors [3] = "Credit card number is invalid";
ccErrors [4] = "Credit card number has an inappropriate number of digits";

function checkCreditCard (cardnumber, cardname) {

     
  // Array to hold the permitted card characteristics
  var cards = new Array();

  // Define the cards we support. You may add addtional card types.
  
  //  Name:      As in the selection box of the form - must be same as user's
  //  Length:    List of possible valid lengths of the card number for the card
  //  prefixes:  List of possible prefixes for the card
  //  checkdigit Boolean to say whether there is a check digit
  
  cards [0] = {name: "Visa", 
               length: "13,16", 
               prefixes: "4",
               checkdigit: true};
  cards [1] = {name: "MasterCard", 
               length: "16", 
               prefixes: "51,52,53,54,55",
               checkdigit: true};
  cards [2] = {name: "DinersClub", 
               length: "14,16", 
               prefixes: "300,301,302,303,304,305,36,38,55",
               checkdigit: true};
  cards [3] = {name: "CarteBlanche", 
               length: "14", 
               prefixes: "300,301,302,303,304,305,36,38",
               checkdigit: true};
  cards [4] = {name: "American Express", 
               length: "15", 
               prefixes: "34,37",
               checkdigit: true};
  cards [5] = {name: "Discover", 
               length: "16", 
               prefixes: "6011,650",
               checkdigit: true};
  cards [6] = {name: "JCB", 
               length: "15,16", 
               prefixes: "3,1800,2131",
               checkdigit: true};
  cards [7] = {name: "enRoute", 
               length: "15", 
               prefixes: "2014,2149",
               checkdigit: true};
  cards [8] = {name: "Solo", 
               length: "16,18,19", 
               prefixes: "6334, 6767",
               checkdigit: true};
  cards [9] = {name: "Switch", 
               length: "16,18,19", 
               prefixes: "4903,4905,4911,4936,564182,633110,6333,6759",
               checkdigit: true};
  cards [10] = {name: "Maestro", 
               length: "16", 
               prefixes: "5020,6",
               checkdigit: true};
  cards [11] = {name: "VisaElectron", 
               length: "16", 
               prefixes: "417500,4917,4913",
               checkdigit: true};
               
  // Establish card type
  var cardType = -1;
  for (var i=0; i<cards.length; i++) {

    // See if it is this card (ignoring the case of the string)
    if (cardname.toLowerCase () == cards[i].name.toLowerCase()) {
      cardType = i;
      break;
    }
  }
  
  // If card type not found, report an error
  if (cardType == -1) {
     ccErrorNo = 0;
     return false; 
  }
   
  // Ensure that the user has provided a credit card number
  if (cardnumber.length == 0)  {
     ccErrorNo = 1;
     return false; 
  }
  
  // Check that the number is numeric, although we do permit a space to occur  
  // every four digits. 
  var cardNo = cardnumber
  var cardexp = /^([0-9]{4})\s?([0-9]{4})\s?([0-9]{4})\s?([0-9]{1,4})$/;
  if (!cardexp.exec(cardNo))  {
     ccErrorNo = 2;
     return false; 
  }
    
  // Now remove any spaces from the credit card number
  cardexp.exec(cardNo);
  cardNo = RegExp.$1 + RegExp.$2 + RegExp.$3 + RegExp.$4;
       
  // Now check the modulus 10 check digit - if required
  if (cards[cardType].checkdigit) {
    var checksum = 0;                                  // running checksum total
    var mychar = "";                                   // next char to process
    var j = 1;                                         // takes value of 1 or 2
  
    // Process each digit one by one starting at the right
    var calc;
    for (i = cardNo.length - 1; i >= 0; i--) {
    
      // Extract the next digit and multiply by 1 or 2 on alternative digits.
      calc = Number(cardNo.charAt(i)) * j;
    
      // If the result is in two digits add 1 to the checksum total
      if (calc > 9) {
        checksum = checksum + 1;
        calc = calc - 10;
      }
    
      // Add the units element to the checksum total
      checksum = checksum + calc;
    
      // Switch the value of j
      if (j ==1) {j = 2} else {j = 1};
    } 
  
    // All done - if checksum is divisible by 10, it is a valid modulus 10.
    // If not, report an error.
    if (checksum % 10 != 0)  {
     ccErrorNo = 3;
     return false; 
    }
  }  

  // The following are the card-specific checks we undertake.
  var LengthValid = false;
  var PrefixValid = false; 
  var undefined; 

  // We use these for holding the valid lengths and prefixes of a card type
  var prefix = new Array ();
  var lengths = new Array ();
    
  // Load an array with the valid prefixes for this card
  prefix = cards[cardType].prefixes.split(",");
      
  // Now see if any of them match what we have in the card number
  for (i=0; i<prefix.length; i++) {
    var exp = new RegExp ("^" + prefix[i]);
    if (exp.test (cardNo)) PrefixValid = true;
  }
      
  // If it isn't a valid prefix there's no point at looking at the length
  if (!PrefixValid) {
     ccErrorNo = 3;
     return false; 
  }
    
  // See if the length is valid for this card
  lengths = cards[cardType].length.split(",");
  for (j=0; j<lengths.length; j++) {
    if (cardNo.length == lengths[j]) LengthValid = true;
  }
  
  // See if all is OK by seeing if the length was valid. We only check the 
  // length if all else was hunky dory.
  if (!LengthValid) {
     ccErrorNo = 4;
     return false; 
  };   
  
  // The credit card is in the required format.
  return true;
}

function clearForm(formIdent) { 
  var form, elements, i, elm; 
  form = document.getElementById 
    ? document.getElementById(formIdent) 
    : document.forms[formIdent]; 

	if (document.getElementsByTagName) {
		elements = form.getElementsByTagName('input');
		for( i=0, elm; elm=elements.item(i++); )
		{
			if (elm.getAttribute('type') == "text")
			{
				elm.value = '';
			}
		}
	}

	// Actually looking through more elements here
	// but the result is the same.
	else
	{
		elements = form.elements;
		for( i=0, elm; elm=elements[i++]; )
		{
			if (elm.type == "text")
			{
				elm.value ='';
			}
		}
	}
}


/*============================================================================*/