// Form Validation Functions  v1.1.6
// http://www.dithered.com/javascript/form_validation/index.html
// code by Chris Nott (chris@NOSPAMdithered.com - remove NOSPAM)


function getFormErrors(form) {
   var errors = new Array();
   
   // loop thru all form elements
   for (var elementIndex = 0; elementIndex < form.elements.length; elementIndex++) {
      var element = form.elements[elementIndex];
     
      // text and textarea types
      if (element.type == "text" || element.type == "textarea") {
         element.value = trimWhitespace(element.value)
         
         // required element
         if (element.required  && element.value == '') {
            errors[errors.length] = element.requiredError;
         }
         
         // maximum length
         else if (element.maxlength && isValidLength(element.value, 0, element.maxlength) == false) {
            errors[errors.length] = element.maxlengthError;
         }

         // minimum length
         else if (element.minlength && isValidLength(element.value, element.minlength, Number.MAX_VALUE) == false) {
            errors[errors.length] = element.minlengthError;
         }
         
         // pattern (credit card number, email address, zip or postal code, alphanumeric, numeric)
         else if (element.pattern) {
            if (  (element.pattern.toLowerCase() == 'email' && isValidEmailStrict(element.value) == false) ||
                  (element.pattern.toLowerCase() == 'us phone number' && 
                     ( (element.prefix && element.suffix && isValidUSPhoneNumber(element.value, form[element.prefix].value, form[element.suffix].value) == false) || 
                        (!element.prefix && !element.suffix && isValidUSPhoneNumber(element.value) == false) ) ) ||
                  (element.pattern.toLowerCase() == 'alphanumeric' && isAlphanumeric(element.value, true) == false) ||
                  (element.pattern.toLowerCase() == 'numeric' && isNumeric(element.value, true) == false) ||
                  (element.pattern.toLowerCase() == 'alphabetic' && isAlphabetic(element.value, true) == false) ) {
               errors[errors.length] = element.patternError;
            }
         }
      }
      
   }
   
	return errors;
}

// Check that the number of characters in a string is between a max and a min
function isValidLength(string, min, max) {
	if (string.length < min || string.length > max) return false;
	else return true;
}

// Check that an email address is valid based on RFC 821 (?)
function isValidEmail(address) {
	if (address != '' && address.search) {
      if (address.search(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/) != -1) return true;
      else return false;
	}
	
   // allow empty strings to return true - screen these with either a 'required' test or a 'length' test
   else return true;
}

// Check that an email address has the form something@something.something
// This is a stricter standard than RFC 821 (?) which allows addresses like postmaster@localhost
function isValidEmailStrict(address) {
	if (isValidEmail(address) == false) return false;
	var domain = address.substring(address.indexOf('@') + 1);
	if (domain.indexOf('.') == -1) return false;
	if (domain.indexOf('.') == 0 || domain.indexOf('.') == domain.length - 1) return false;
	return true;
}


// Check that a US or Canadian phone number is valid
function isValidUSPhoneNumber(areaCode, prefixNumber, suffixNumber) {
   if (arguments.length == 1) {
      var phoneNumber = arguments[0];
      phoneNumber = phoneNumber.replace(/\D+/g, '');
      var length = phoneNumber.length;
      if (phoneNumber.length >= 7) {
         var areaCode = phoneNumber.substring(0, length-7);
         var prefixNumber = phoneNumber.substring(length-7, length-4);
         var suffixNumber = phoneNumber.substring(length-4);
      }
      else return false;
   }
   else if (arguments.length == 3) {
      var areaCode = arguments[0];
      var prefixNumber = arguments[1];
      var suffixNumber = arguments[2];
   }
   else return true;

   if (areaCode.length != 3 || !isNumeric(areaCode) || prefixNumber.length != 3 || !isNumeric(prefixNumber) || suffixNumber.length != 4 || !isNumeric(suffixNumber)) return false;
   return true;
}

// Check that a string contains only letters and numbers
function isAlphanumeric(string, ignoreWhiteSpace) {
	if (string.search) {
		if ((ignoreWhiteSpace && string.search(/[^\w\s]/) != -1) || (!ignoreWhiteSpace && string.search(/\W/) != -1)) return false;
	}
	return true;
}

// Check that a string contains only letters
function isAlphabetic(string, ignoreWhiteSpace) {
	if (string.search) {
		if ((ignoreWhiteSpace && string.search(/[^a-zA-Z\s]/) != -1) || (!ignoreWhiteSpace && string.search(/[^a-zA-Z]/) != -1)) return false;
	}
	return true;
}

// Check that a string contains only numbers
function isNumeric(string, ignoreWhiteSpace) {
	if (string.search) {
		if ((ignoreWhiteSpace && string.search(/[^\d\s]/) != -1) || (!ignoreWhiteSpace && string.search(/\D/) != -1)) return false;
	}
	return true;
}

// Remove leading and trailing whitespace from a string
function trimWhitespace(string) {
	var newString  = '';
	var substring  = '';
	beginningFound = false;
	
	// copy characters over to a new string
	// retain whitespace characters if they are between other characters
	for (var i = 0; i < string.length; i++) {
		
		// copy non-whitespace characters
		if (string.charAt(i) != ' ' && string.charCodeAt(i) != 9) {
			
			// if the temporary string contains some whitespace characters, copy them first
			if (substring != '') {
				newString += substring;
				substring = '';
			}
			newString += string.charAt(i);
			if (beginningFound == false) beginningFound = true;
		}
		
		// hold whitespace characters in a temporary string if they follow a non-whitespace character
		else if (beginningFound == true) substring += string.charAt(i);
	}
	return newString;
}