// LiveValidation 1.3 (standalone version)
// Copyright (c) 2007-2008 Alec Hill (www.livevalidation.com)
// LiveValidation is licensed under the terms of the MIT License

/*********************************************** LiveValidation class ***********************************/

/**
 *	validates a form field in real-time based on validations you assign to it
 *	
 *	@var element {mixed} - either a dom element reference or the string id of the element to validate
 *	@var optionsObj {Object} - general options, see below for details
 *
 *	optionsObj properties:
 *							validMessage {String} 	- the message to show when the field passes validation
 *													  (DEFAULT: "Thankyou!")
 *							onValid {Function} 		- function to execute when field passes validation
 *													  (DEFAULT: function(){ this.insertMessage(this.createMessageSpan()); this.addFieldClass(); } )	
 *							onInvalid {Function} 	- function to execute when field fails validation
 *													  (DEFAULT: function(){ this.insertMessage(this.createMessageSpan()); this.addFieldClass(); })
 *							insertAfterWhatNode {Int} 	- position to insert default message
 *													  (DEFAULT: the field that is being validated)	
 *              onlyOnBlur {Boolean} - whether you want it to validate as you type or only on blur
 *                            (DEFAULT: false)
 *              wait {Integer} - the time you want it to pause from the last keystroke before it validates (ms)
 *                            (DEFAULT: 0)
 *              onlyOnSubmit {Boolean} - whether should be validated only when the form it belongs to is submitted
 *                            (DEFAULT: false)						
 */
var LiveValidation = function(element, optionsObj){
  	this.initialize(element, optionsObj);
}

LiveValidation.VERSION = '1.3 standalone';

/** element types constants ****/

LiveValidation.TEXTAREA 		= 1;
LiveValidation.TEXT 			    = 2;
LiveValidation.PASSWORD 		= 3;
LiveValidation.CHECKBOX 		= 4;
LiveValidation.SELECT = 5;
LiveValidation.FILE = 6;

/****** Static methods *******/

/**
 *	pass an array of LiveValidation objects and it will validate all of them
 *	
 *	@var validations {Array} - an array of LiveValidation objects
 *	@return {Bool} - true if all passed validation, false if any fail						
 */
LiveValidation.massValidate = function(validations){
  var returnValue = true;
	for(var i = 0, len = validations.length; i < len; ++i ){
		var valid = validations[i].validate();
		if(returnValue) returnValue = valid;
	}
	return returnValue;
}

/****** prototype ******/

LiveValidation.prototype = {

    validClass: 'LV_valid',
    invalidClass: 'LV_invalid',
    messageClass: 'LV_validation_message',
    validFieldClass: 'LV_valid_field',
    invalidFieldClass: 'LV_invalid_field',

    /**
    *	initialises all of the properties and events
    *
    * @var - Same as constructor above
    */
    initialize: function(element, optionsObj) {
        var self = this;
        if (!element) throw new Error("LiveValidation::initialize - No element reference or element id has been provided!");
        this.element = element.nodeName ? element : document.getElementById(element);
        if (!this.element) throw new Error("LiveValidation::initialize - No element with reference or id of '" + element + "' exists!");
        // default properties that could not be initialised above
        this.validations = [];
        this.elementType = this.getElementType();
        this.form = this.element.form;
        // options
        var options = optionsObj || {};
        this.validMessage = options.validMessage || '';
        /*'Thankyou!';*/
        var node = options.insertAfterWhatNode || this.element;
        this.insertAfterWhatNode = node.nodeType ? node : document.getElementById(node);
        this.onValid = options.onValid || function() { this.insertMessage(this.createMessageSpan()); this.addFieldClass(); };
        this.onInvalid = options.onInvalid || function() { this.insertMessage(this.createMessageSpan()); this.addFieldClass(); };
        this.onlyOnBlur = options.onlyOnBlur || false;
        this.wait = options.wait || 0;
        this.onlyOnSubmit = options.onlyOnSubmit || false;
        // add to form if it has been provided
        if (this.form) {
            this.formObj = LiveValidationForm.getInstance(this.form);
            this.formObj.addField(this);
        }
        // events
        // collect old events
        this.oldOnFocus = this.element.onfocus || function() { };
        this.oldOnBlur = this.element.onblur || function() { };
        this.oldOnClick = this.element.onclick || function() { };
        this.oldOnChange = this.element.onchange || function() { };
        this.oldOnKeyup = this.element.onkeyup || function() { };
        this.element.onfocus = function(e) { self.doOnFocus(e); return self.oldOnFocus.call(this, e); }
        if (!this.onlyOnSubmit) {
            switch (this.elementType) {
                case LiveValidation.CHECKBOX:
                    this.element.onclick = function(e) { self.validate(); return self.oldOnClick.call(this, e); }
                    // let it run into the next to add a change event too
                case LiveValidation.SELECT:
                case LiveValidation.FILE:
                    this.element.onchange = function(e) { self.validate(); return self.oldOnChange.call(this, e); }
                    break;
                default:
                    if (!this.onlyOnBlur) this.element.onkeyup = function(e) { self.deferValidation(); return self.oldOnKeyup.call(this, e); }
                    this.element.onblur = function(e) { self.doOnBlur(e); return self.oldOnBlur.call(this, e); }
            }
        }
    },

    /**
    *	destroys the instance's events (restoring previous ones) and removes it from any LiveValidationForms
    */
    destroy: function() {
        if (this.formObj) {
            // remove the field from the LiveValidationForm
            this.formObj.removeField(this);
            // destroy the LiveValidationForm if no LiveValidation fields left in it
            this.formObj.destroy();
        }
        // remove events - set them back to the previous events
        this.element.onfocus = this.oldOnFocus;
        if (!this.onlyOnSubmit) {
            switch (this.elementType) {
                case LiveValidation.CHECKBOX:
                    this.element.onclick = this.oldOnClick;
                    // let it run into the next to add a change event too
                case LiveValidation.SELECT:
                case LiveValidation.FILE:
                    this.element.onchange = this.oldOnChange;
                    break;
                default:
                    if (!this.onlyOnBlur) this.element.onkeyup = this.oldOnKeyup;
                    this.element.onblur = this.oldOnBlur;
            }
        }
        this.validations = [];
        this.removeMessageAndFieldClass();
    },

    /**
    *	adds a validation to perform to a LiveValidation object
    *
    *	@var validationFunction {Function} - validation function to be used (ie Validate.Presence )
    *	@var validationParamsObj {Object} - parameters for doing the validation, if wanted or necessary
    * @return {Object} - the LiveValidation object itself so that calls can be chained
    */
    add: function(validationFunction, validationParamsObj) {
        this.validations.push({ type: validationFunction, params: validationParamsObj || {} });
        return this;
    },

    /**
    *	removes a validation from a LiveValidation object - must have exactly the same arguments as used to add it 
    *
    *	@var validationFunction {Function} - validation function to be used (ie Validate.Presence )
    *	@var validationParamsObj {Object} - parameters for doing the validation, if wanted or necessary
    * @return {Object} - the LiveValidation object itself so that calls can be chained
    */
    remove: function(validationFunction, validationParamsObj) {
        var found = false;
        for (var i = 0, len = this.validations.length; i < len; i++) {
            if (this.validations[i].type == validationFunction) {
                if (this.validations[i].params == validationParamsObj) {
                    found = true;
                    break;
                }
            }
        }
        if (found) this.validations.splice(i, 1);
        return this;
    },


    /**
    * makes the validation wait the alotted time from the last keystroke 
    */
    deferValidation: function(e) {
        if (this.wait >= 300) this.removeMessageAndFieldClass();
        var self = this;
        if (this.timeout) clearTimeout(self.timeout);
        this.timeout = setTimeout(function() { self.validate() }, self.wait);
    },

    /**
    * sets the focused flag to false when field loses focus 
    */
    doOnBlur: function(e) {
        this.focused = false;
        this.validate(e);
    },

    /**
    * sets the focused flag to true when field gains focus 
    */
    doOnFocus: function(e) {
        this.focused = true;
        this.removeMessageAndFieldClass();
    },

    /**
    *	gets the type of element, to check whether it is compatible
    *
    *	@var validationFunction {Function} - validation function to be used (ie Validate.Presence )
    *	@var validationParamsObj {Object} - parameters for doing the validation, if wanted or necessary
    */
    getElementType: function() {
        switch (true) {
            case (this.element.nodeName.toUpperCase() == 'TEXTAREA'):
                return LiveValidation.TEXTAREA;
            case (this.element.nodeName.toUpperCase() == 'INPUT' && this.element.type.toUpperCase() == 'TEXT'):
                return LiveValidation.TEXT;
            case (this.element.nodeName.toUpperCase() == 'INPUT' && this.element.type.toUpperCase() == 'PASSWORD'):
                return LiveValidation.PASSWORD;
            case (this.element.nodeName.toUpperCase() == 'INPUT' && this.element.type.toUpperCase() == 'CHECKBOX'):
                return LiveValidation.CHECKBOX;
            case (this.element.nodeName.toUpperCase() == 'INPUT' && this.element.type.toUpperCase() == 'FILE'):
                return LiveValidation.FILE;
            case (this.element.nodeName.toUpperCase() == 'SELECT'):
                return LiveValidation.SELECT;
            case (this.element.nodeName.toUpperCase() == 'INPUT'):
                throw new Error('LiveValidation::getElementType - Cannot use LiveValidation on an ' + this.element.type + ' input!');
            default:
                throw new Error('LiveValidation::getElementType - Element must be an input, select, or textarea!');
        }
    },

    /**
    *	loops through all the validations added to the LiveValidation object and checks them one by one
    *
    *	@var validationFunction {Function} - validation function to be used (ie Validate.Presence )
    *	@var validationParamsObj {Object} - parameters for doing the validation, if wanted or necessary
    * @return {Boolean} - whether the all the validations passed or if one failed
    */
    doValidations: function() {
        this.validationFailed = false;
        for (var i = 0, len = this.validations.length; i < len; ++i) {
            var validation = this.validations[i];
            switch (validation.type) {
                case Validate.Presence:
                case Validate.Confirmation:
                case Validate.Acceptance:
                    this.displayMessageWhenEmpty = true;
                    this.validationFailed = !this.validateElement(validation.type, validation.params);
                    break;
                default:
                    this.validationFailed = !this.validateElement(validation.type, validation.params);
                    break;
            }
            if (this.validationFailed) return false;
        }
        this.message = this.validMessage;
        return true;
    },

    /**
    *	performs validation on the element and handles any error (validation or otherwise) it throws up
    *
    *	@var validationFunction {Function} - validation function to be used (ie Validate.Presence )
    *	@var validationParamsObj {Object} - parameters for doing the validation, if wanted or necessary
    * @return {Boolean} - whether the validation has passed or failed
    */
    validateElement: function(validationFunction, validationParamsObj) {
        var value = (this.elementType == LiveValidation.SELECT) ? this.element.options[this.element.selectedIndex].value : this.element.value;
        if (validationFunction == Validate.Acceptance) {
            if (this.elementType != LiveValidation.CHECKBOX) throw new Error('LiveValidation::validateElement - Element to validate acceptance must be a checkbox!');
            value = this.element.checked;
        }
        var isValid = true;
        try {
            validationFunction(value, validationParamsObj);
        } catch (error) {
            if (error instanceof Validate.Error) {
                if (value !== '' || (value === '' && this.displayMessageWhenEmpty)) {
                    this.validationFailed = true;
                    this.message = error.message;
                    isValid = false;
                }
            } else {
                throw error;
            }
        } finally {
            return isValid;
        }
    },

    /**
    *	makes it do the all the validations and fires off the onValid or onInvalid callbacks
    *
    * @return {Boolean} - whether the all the validations passed or if one failed
    */
    validate: function() {
        if (!this.element.disabled) {
            var isValid = this.doValidations();
            if (isValid) {
                this.onValid();
                return true;
            } else {
                this.onInvalid();
                return false;
            }
        } else {
            return true;
        }
    },

    /**
    *  enables the field
    *
    *  @return {LiveValidation} - the LiveValidation object for chaining
    */
    enable: function() {
        this.element.disabled = false;
        return this;
    },

    /**
    *  disables the field and removes any message and styles associated with the field
    *
    *  @return {LiveValidation} - the LiveValidation object for chaining
    */
    disable: function() {
        this.element.disabled = true;
        this.removeMessageAndFieldClass();
        return this;
    },

    /** Message insertion methods ****************************
    * 
    * These are only used in the onValid and onInvalid callback functions and so if you overide the default callbacks,
    * you must either impliment your own functions to do whatever you want, or call some of these from them if you 
    * want to keep some of the functionality
    */

    /**
    *	makes a span containg the passed or failed message
    *
    * @return {HTMLSpanObject} - a span element with the message in it
    */
    createMessageSpan: function() {
        var span = document.createElement('span');
        var textNode = document.createTextNode(this.message);
        span.appendChild(textNode);
        return span;
    },

    /**
    *	inserts the element containing the message in place of the element that already exists (if it does)
    *
    * @var elementToIsert {HTMLElementObject} - an element node to insert
    */
    insertMessage: function(elementToInsert) {
        this.removeMessage();
        if ((this.displayMessageWhenEmpty && (this.elementType == LiveValidation.CHECKBOX || this.element.value == ''))
    	  || this.element.value != '') {
            var className = this.validationFailed ? this.invalidClass : this.validClass;
            elementToInsert.className += ' ' + this.messageClass + ' ' + className;
            if (this.insertAfterWhatNode.nextSibling) {
                this.insertAfterWhatNode.parentNode.insertBefore(elementToInsert, this.insertAfterWhatNode.nextSibling);
            } else {
                this.insertAfterWhatNode.parentNode.appendChild(elementToInsert);
            }
        }
    },


    /**
    *	changes the class of the field based on whether it is valid or not
    */
    addFieldClass: function() {
        this.removeFieldClass();
        if (!this.validationFailed) {
            if (this.displayMessageWhenEmpty || this.element.value != '') {
                if (this.element.className.indexOf(this.validFieldClass) == -1) this.element.className += ' ' + this.validFieldClass;
            }
        } else {
            if (this.element.className.indexOf(this.invalidFieldClass) == -1) this.element.className += ' ' + this.invalidFieldClass;
        }
    },

    /**
    *	removes the message element if it exists, so that the new message will replace it
    */
    removeMessage: function() {
        var nextEl;
        var el = this.insertAfterWhatNode;
        while (el.nextSibling) {
            if (el.nextSibling.nodeType === 1) {
                nextEl = el.nextSibling;
                break;
            }
            el = el.nextSibling;
        }
        if (nextEl && nextEl.className.indexOf(this.messageClass) != -1) this.insertAfterWhatNode.parentNode.removeChild(nextEl);
    },

    /**
    *	removes the class that has been applied to the field to indicte if valid or not
    */
    removeFieldClass: function() {
        if (this.element.className.indexOf(this.invalidFieldClass) != -1) this.element.className = this.element.className.split(this.invalidFieldClass).join('');
        if (this.element.className.indexOf(this.validFieldClass) != -1) this.element.className = this.element.className.split(this.validFieldClass).join(' ');
    },

    /**
    *	removes the message and the field class
    */
    removeMessageAndFieldClass: function() {
        this.removeMessage();
        this.removeFieldClass();
    }

} // end of LiveValidation class

/*************************************** LiveValidationForm class ****************************************/
/**
 * This class is used internally by LiveValidation class to associate a LiveValidation field with a form it is icontained in one
 * 
 * It will therefore not really ever be needed to be used directly by the developer, unless they want to associate a LiveValidation 
 * field with a form that it is not a child of
 */

/**
   *	handles validation of LiveValidation fields belonging to this form on its submittal
   *	
   *	@var element {HTMLFormElement} - a dom element reference to the form to turn into a LiveValidationForm
   */
var LiveValidationForm = function(element){
  this.initialize(element);
}

/**
 * namespace to hold instances
 */
LiveValidationForm.instances = {};

/**
   *	gets the instance of the LiveValidationForm if it has already been made or creates it if it doesnt exist
   *	
   *	@var element {HTMLFormElement} - a dom element reference to a form
   */
LiveValidationForm.getInstance = function(element){
  var rand = Math.random() * Math.random();
  if(!element.id) element.id = 'formId_' + rand.toString().replace(/\./, '') + new Date().valueOf();
  if(!LiveValidationForm.instances[element.id]) LiveValidationForm.instances[element.id] = new LiveValidationForm(element);
  return LiveValidationForm.instances[element.id];
}

LiveValidationForm.prototype = {
  
  /**
   *	constructor for LiveValidationForm - handles validation of LiveValidation fields belonging to this form on its submittal
   *	
   *	@var element {HTMLFormElement} - a dom element reference to the form to turn into a LiveValidationForm
   */
  initialize: function(element){
  	this.name = element.id;
    this.element = element;
    this.fields = [];
    // preserve the old onsubmit event
	this.oldOnSubmit = this.element.onsubmit || function(){};
    var self = this;
    this.element.onsubmit = function(e){
      return (LiveValidation.massValidate(self.fields)) ? self.oldOnSubmit.call(this, e || window.event) !== false : false;
    }
  },
  
  /**
   *	adds a LiveValidation field to the forms fields array
   *	
   *	@var element {LiveValidation} - a LiveValidation object
   */
  addField: function(newField){
    this.fields.push(newField);
  },
  
  /**
   *	removes a LiveValidation field from the forms fields array
   *	
   *	@var victim {LiveValidation} - a LiveValidation object
   */
  removeField: function(victim){
  	var victimless = [];
  	for( var i = 0, len = this.fields.length; i < len; i++){
		if(this.fields[i] !== victim) victimless.push(this.fields[i]);
	}
    this.fields = victimless;
  },
  
  /**
   *	destroy this instance and its events
   *
   * @var force {Boolean} - whether to force the detruction even if there are fields still associated
   */
  destroy: function(force){
  	// only destroy if has no fields and not being forced
  	if (this.fields.length != 0 && !force) return false;
	// remove events - set back to previous events
	this.element.onsubmit = this.oldOnSubmit;
	// remove from the instances namespace
	LiveValidationForm.instances[this.name] = null;
	return true;
  }
   
}// end of LiveValidationForm prototype

/*************************************** Validate class ****************************************/
/**
 * This class contains all the methods needed for doing the actual validation itself
 *
 * All methods are static so that they can be used outside the context of a form field
 * as they could be useful for validating stuff anywhere you want really
 *
 * All of them will return true if the validation is successful, but will raise a ValidationError if
 * they fail, so that this can be caught and the message explaining the error can be accessed ( as just 
 * returning false would leave you a bit in the dark as to why it failed )
 *
 * Can use validation methods alone and wrap in a try..catch statement yourself if you want to access the failure
 * message and handle the error, or use the Validate::now method if you just want true or false
 */

var Validate = {

    /**
    *	validates that the field has been filled in
    *
    *	@var value {mixed} - value to be checked
    *	@var paramsObj {Object} - parameters for this particular validation, see below for details
    *
    *	paramsObj properties:
    *							failureMessage {String} - the message to show when the field fails validation 
    *													  (DEFAULT: "Can't be empty!")
    */
    Presence: function(value, paramsObj) {
        var paramsObj = paramsObj || {};
        var message = paramsObj.failureMessage || "";
        /*Can't be empty!";*/
        if (value === '' || value === null || value === undefined) {
            Validate.fail(message);
        }
        return true;
    },

    /**
    *	validates that the value is numeric, does not fall within a given range of numbers
    *	
    *	@var value {mixed} - value to be checked
    *	@var paramsObj {Object} - parameters for this particular validation, see below for details
    *
    *	paramsObj properties:
    *							notANumberMessage {String} - the message to show when the validation fails when value is not a number
    *													  	  (DEFAULT: "Must be a number!")
    *							notAnIntegerMessage {String} - the message to show when the validation fails when value is not an integer
    *													  	  (DEFAULT: "Must be a number!")
    *							wrongNumberMessage {String} - the message to show when the validation fails when is param is used
    *													  	  (DEFAULT: "Must be {is}!")
    *							tooLowMessage {String} 		- the message to show when the validation fails when minimum param is used
    *													  	  (DEFAULT: "Must not be less than {minimum}!")
    *							tooHighMessage {String} 	- the message to show when the validation fails when maximum param is used
    *													  	  (DEFAULT: "Must not be more than {maximum}!")
    *							is {Int} 					- the length must be this long 
    *							minimum {Int} 				- the minimum length allowed
    *							maximum {Int} 				- the maximum length allowed
    *                         onlyInteger {Boolean} - if true will only allow integers to be valid
    *                                                             (DEFAULT: false)
    *
    *  NB. can be checked if it is within a range by specifying both a minimum and a maximum
    *  NB. will evaluate numbers represented in scientific form (ie 2e10) correctly as numbers				
    */
    Numericality: function(value, paramsObj) {
        var suppliedValue = value;
        var value = Number(value);
        var paramsObj = paramsObj || {};
        var minimum = ((paramsObj.minimum) || (paramsObj.minimum == 0)) ? paramsObj.minimum : null; ;
        var maximum = ((paramsObj.maximum) || (paramsObj.maximum == 0)) ? paramsObj.maximum : null;
        var is = ((paramsObj.is) || (paramsObj.is == 0)) ? paramsObj.is : null;
        var notANumberMessage = paramsObj.notANumberMessage || "";
        /*"Must be a number!";*/
        var notAnIntegerMessage = paramsObj.notAnIntegerMessage || "";
        /*"Must be an integer!";*/
        var wrongNumberMessage = paramsObj.wrongNumberMessage || "Must be " + is + "!";
        var tooLowMessage = paramsObj.tooLowMessage || "Must not be less than " + minimum + "!";
        var tooHighMessage = paramsObj.tooHighMessage || "Must not be more than " + maximum + "!";
        if (!isFinite(value)) Validate.fail(notANumberMessage);
        if (paramsObj.onlyInteger && (/\.0+$|\.$/.test(String(suppliedValue)) || value != parseInt(value))) Validate.fail(notAnIntegerMessage);
        switch (true) {
            case (is !== null):
                if (value != Number(is)) Validate.fail(wrongNumberMessage);
                break;
            case (minimum !== null && maximum !== null):
                Validate.Numericality(value, { tooLowMessage: tooLowMessage, minimum: minimum });
                Validate.Numericality(value, { tooHighMessage: tooHighMessage, maximum: maximum });
                break;
            case (minimum !== null):
                if (value < Number(minimum)) Validate.fail(tooLowMessage);
                break;
            case (maximum !== null):
                if (value > Number(maximum)) Validate.fail(tooHighMessage);
                break;
        }
        return true;
    },

    /**
    *	validates against a RegExp pattern
    *	
    *	@var value {mixed} - value to be checked
    *	@var paramsObj {Object} - parameters for this particular validation, see below for details
    *
    *	paramsObj properties:
    *							failureMessage {String} - the message to show when the field fails validation
    *													  (DEFAULT: "Not valid!")
    *							pattern {RegExp} 		- the regular expression pattern
    *													  (DEFAULT: /./)
    *             negate {Boolean} - if set to true, will validate true if the pattern is not matched
    *                           (DEFAULT: false)
    *
    *  NB. will return true for an empty string, to allow for non-required, empty fields to validate.
    *		If you do not want this to be the case then you must either add a LiveValidation.PRESENCE validation
    *		or build it into the regular expression pattern
    */
    Format: function(value, paramsObj) {
        var value = String(value);
        var paramsObj = paramsObj || {};
        var message = paramsObj.failureMessage || "Not valid!";
        var pattern = paramsObj.pattern || /./;
        var negate = paramsObj.negate || false;
        if (!negate && !pattern.test(value)) Validate.fail(message); // normal
        if (negate && pattern.test(value)) Validate.fail(message); // negated
        return true;
    },

    /**
    *	validates that the field contains a valid email address
    *	
    *	@var value {mixed} - value to be checked
    *	@var paramsObj {Object} - parameters for this particular validation, see below for details
    *
    *	paramsObj properties:
    *							failureMessage {String} - the message to show when the field fails validation
    *													  (DEFAULT: "Must be a number!" or "Must be an integer!")
    */
    Email: function(value, paramsObj) {
        var paramsObj = paramsObj || {};
        var message = paramsObj.failureMessage || "Must be a valid email address!";
        Validate.Format(value, { failureMessage: message, pattern: /^([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})$/i });
        return true;
    },

    /**
    *	validates the length of the value
    *	
    *	@var value {mixed} - value to be checked
    *	@var paramsObj {Object} - parameters for this particular validation, see below for details
    *
    *	paramsObj properties:
    *							wrongLengthMessage {String} - the message to show when the fails when is param is used
    *													  	  (DEFAULT: "Must be {is} characters long!")
    *							tooShortMessage {String} 	- the message to show when the fails when minimum param is used
    *													  	  (DEFAULT: "Must not be less than {minimum} characters long!")
    *							tooLongMessage {String} 	- the message to show when the fails when maximum param is used
    *													  	  (DEFAULT: "Must not be more than {maximum} characters long!")
    *							is {Int} 					- the length must be this long 
    *							minimum {Int} 				- the minimum length allowed
    *							maximum {Int} 				- the maximum length allowed
    *
    *  NB. can be checked if it is within a range by specifying both a minimum and a maximum				
    */
    Length: function(value, paramsObj) {
        var value = String(value);
        var paramsObj = paramsObj || {};
        var minimum = ((paramsObj.minimum) || (paramsObj.minimum == 0)) ? paramsObj.minimum : null;
        var maximum = ((paramsObj.maximum) || (paramsObj.maximum == 0)) ? paramsObj.maximum : null;
        var is = ((paramsObj.is) || (paramsObj.is == 0)) ? paramsObj.is : null;
        var wrongLengthMessage = paramsObj.wrongLengthMessage || "";
        /*"Must be " + is + " characters long!";*/
        var tooShortMessage = paramsObj.tooShortMessage || "Must not be less than " + minimum + " characters long!";
        var tooLongMessage = paramsObj.tooLongMessage || "Must not be more than " + maximum + " characters long!";
        switch (true) {
            case (is !== null):
                if (value.length != Number(is)) Validate.fail(wrongLengthMessage);
                break;
            case (minimum !== null && maximum !== null):
                Validate.Length(value, { tooShortMessage: tooShortMessage, minimum: minimum });
                Validate.Length(value, { tooLongMessage: tooLongMessage, maximum: maximum });
                break;
            case (minimum !== null):
                if (value.length < Number(minimum)) Validate.fail(tooShortMessage);
                break;
            case (maximum !== null):
                if (value.length > Number(maximum)) Validate.fail(tooLongMessage);
                break;
            default:
                throw new Error("Validate::Length - Length(s) to validate against must be provided!");
        }
        return true;
    },

    /**
    *	validates that the value falls within a given set of values
    *	
    *	@var value {mixed} - value to be checked
    *	@var paramsObj {Object} - parameters for this particular validation, see below for details
    *
    *	paramsObj properties:
    *							failureMessage {String} - the message to show when the field fails validation
    *													  (DEFAULT: "Must be included in the list!")
    *							within {Array} 			- an array of values that the value should fall in 
    *													  (DEFAULT: [])	
    *							allowNull {Bool} 		- if true, and a null value is passed in, validates as true
    *													  (DEFAULT: false)
    *             partialMatch {Bool} 	- if true, will not only validate against the whole value to check but also if it is a substring of the value 
    *													  (DEFAULT: false)
    *             caseSensitive {Bool} - if false will compare strings case insensitively
    *                          (DEFAULT: true)
    *             negate {Bool} 		- if true, will validate that the value is not within the given set of values
    *													  (DEFAULT: false)			
    */
    Inclusion: function(value, paramsObj) {
        var paramsObj = paramsObj || {};
        var message = paramsObj.failureMessage || "Must be included in the list!";
        var caseSensitive = (paramsObj.caseSensitive === false) ? false : true;
        if (paramsObj.allowNull && value == null) return true;
        if (!paramsObj.allowNull && value == null) Validate.fail(message);
        var within = paramsObj.within || [];
        //if case insensitive, make all strings in the array lowercase, and the value too
        if (!caseSensitive) {
            var lowerWithin = [];
            for (var j = 0, length = within.length; j < length; ++j) {
                var item = within[j];
                if (typeof item == 'string') item = item.toLowerCase();
                lowerWithin.push(item);
            }
            within = lowerWithin;
            if (typeof value == 'string') value = value.toLowerCase();
        }
        var found = false;
        for (var i = 0, length = within.length; i < length; ++i) {
            if (within[i] == value) found = true;
            if (paramsObj.partialMatch) {
                if (value.indexOf(within[i]) != -1) found = true;
            }
        }
        if ((!paramsObj.negate && !found) || (paramsObj.negate && found)) Validate.fail(message);
        return true;
    },

    /**
    *	validates that the value does not fall within a given set of values
    *	
    *	@var value {mixed} - value to be checked
    *	@var paramsObj {Object} - parameters for this particular validation, see below for details
    *
    *	paramsObj properties:
    *							failureMessage {String} - the message to show when the field fails validation
    *													  (DEFAULT: "Must not be included in the list!")
    *							within {Array} 			- an array of values that the value should not fall in 
    *													  (DEFAULT: [])
    *							allowNull {Bool} 		- if true, and a null value is passed in, validates as true
    *													  (DEFAULT: false)
    *             partialMatch {Bool} 	- if true, will not only validate against the whole value to check but also if it is a substring of the value 
    *													  (DEFAULT: false)
    *             caseSensitive {Bool} - if false will compare strings case insensitively
    *                          (DEFAULT: true)			
    */
    Exclusion: function(value, paramsObj) {
        var paramsObj = paramsObj || {};
        paramsObj.failureMessage = paramsObj.failureMessage || "";
        /*"Must not be included in the list!";*/
        paramsObj.negate = true;
        Validate.Inclusion(value, paramsObj);
        return true;
    },

    /**
    *	validates that the value matches that in another field
    *	
    *	@var value {mixed} - value to be checked
    *	@var paramsObj {Object} - parameters for this particular validation, see below for details
    *
    *	paramsObj properties:
    *							failureMessage {String} - the message to show when the field fails validation
    *													  (DEFAULT: "Does not match!")
    *							match {String} 			- id of the field that this one should match						
    */
    Confirmation: function(value, paramsObj) {
        if (!paramsObj.match) throw new Error("Validate::Confirmation - Error validating confirmation: Id of element to match must be provided!");
        var paramsObj = paramsObj || {};
        var message = paramsObj.failureMessage || "Does not match!";
        var match = paramsObj.match.nodeName ? paramsObj.match : document.getElementById(paramsObj.match);
        if (!match) throw new Error("Validate::Confirmation - There is no reference with name of, or element with id of '" + paramsObj.match + "'!");
        if (value != match.value) {
            Validate.fail(message);
        }
        return true;
    },

    /**
    *	validates that the value is true (for use primarily in detemining if a checkbox has been checked)
    *	
    *	@var value {mixed} - value to be checked if true or not (usually a boolean from the checked value of a checkbox)
    *	@var paramsObj {Object} - parameters for this particular validation, see below for details
    *
    *	paramsObj properties:
    *							failureMessage {String} - the message to show when the field fails validation 
    *													  (DEFAULT: "Must be accepted!")
    */
    Acceptance: function(value, paramsObj) {
        var paramsObj = paramsObj || {};
        var message = paramsObj.failureMessage || "Must be accepted!";
        if (!value) {
            Validate.fail(message);
        }
        return true;
    },

    /**
    *	validates against a custom function that returns true or false (or throws a Validate.Error) when passed the value
    *	
    *	@var value {mixed} - value to be checked
    *	@var paramsObj {Object} - parameters for this particular validation, see below for details
    *
    *	paramsObj properties:
    *							failureMessage {String} - the message to show when the field fails validation
    *													  (DEFAULT: "Not valid!")
    *							against {Function} 			- a function that will take the value and object of arguments and return true or false 
    *													  (DEFAULT: function(){ return true; })
    *							args {Object} 		- an object of named arguments that will be passed to the custom function so are accessible through this object within it 
    *													  (DEFAULT: {})
    */
    Custom: function(value, paramsObj) {
        var paramsObj = paramsObj || {};
        var against = paramsObj.against || function() { return true; };
        var args = paramsObj.args || {};
        var message = paramsObj.failureMessage || "Not valid!";
        if (!against(value, args)) Validate.fail(message);
        return true;
    },

    /**
    *	validates whatever it is you pass in, and handles the validation error for you so it gives a nice true or false reply
    *
    *	@var validationFunction {Function} - validation function to be used (ie Validation.validatePresence )
    *	@var value {mixed} - value to be checked if true or not (usually a boolean from the checked value of a checkbox)
    *	@var validationParamsObj {Object} - parameters for doing the validation, if wanted or necessary
    */
    now: function(validationFunction, value, validationParamsObj) {
        if (!validationFunction) throw new Error("Validate::now - Validation function must be provided!");
        var isValid = true;
        try {
            validationFunction(value, validationParamsObj || {});
        } catch (error) {
            if (error instanceof Validate.Error) {
                isValid = false;
            } else {
                throw error;
            }
        } finally {
            return isValid
        }
    },

    /**
    * shortcut for failing throwing a validation error
    *
    *	@var errorMessage {String} - message to display
    */
    fail: function(errorMessage) {
        throw new Validate.Error(errorMessage);
    },

    Error: function(errorMessage) {
        this.message = errorMessage;
        this.name = 'ValidationError';
    }

}