var ERROR_MSG_HEADER            = 'De volgende velden zijn verkeerd ingevuld';
var ERROR_MSG_REQUIRED          = 'mag niet leeg zijn';
var ERROR_MSG_LONG_TEXT         = 'mag niet langer zijn dan %d karakter(s)';
var ERROR_MSG_ILLEGAL_DATE      = 'ongeldige datum';
var ERROR_MSG_ILLEGAL_EMAIL     = 'ongeldige e-mail adres';
var ERROR_MSG_ILLEGAL_NUMBER    = 'moet een getal zijn';
var ERROR_MSG_CHECKBOX_LIST_MIN = 'er moeten minstens %d keuzevakjes gevinkt zijn';
var ERROR_MSG_CHECKBOX_LIST_MAX = 'er mogen maximaal %d keuzevakjes gevinkt zijn';
var ERROR_MSG_VALUE_UNCHANGED   = 'mag niet ongewijzigd blijven';

var FIELD_NOT_FOUND = -1;

var FORM_RESULT_LEGAL   = 0;
var FORM_RESULT_ADAPT   = 1;
var FORM_RESULT_ILLEGAL = 2;

var VALUE_TYPE_DATA        = "DATA";
var VALUE_TYPE_INFORMATION = "INFORMATION";

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

function submitScript(form) {
  var formFieldReader = new FormFieldReader(form);
  formFieldReader.start();

  var formFields = formFieldReader.getFormFields();
  
  if(formFields.getResult() == FORM_RESULT_LEGAL) {
    form.submit();
  } else if(formFields.getResult() == FORM_RESULT_ADAPT) {
    formFields.adaptFields();
    form.submit();
  } else if(formFields.getResult() == FORM_RESULT_ILLEGAL) {
    alert(formFields.getErrorMessage());
  }
}

function checkPassword(lhs, rhs) {
  passwordValid = true;

  if(lhs.value != rhs.value) {
    alert('Passwords are not equal!');
    passwordValid = false;
  } else if (lhs.value.length < 4) {
    alert('Password requires at least 4 characters!');
    passwordValid = false;
  }
  
  return passwordValid;
}


function isDigit()
{
	return ((event.keyCode >= 48) && (event.keyCode <= 57));
}

function charIsDigit (value){
  return ((value >= "0") && (value <= "9"));
}

function emailValid(emailAddress) {
  var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/ ;
  return filter.test(emailAddress); 
}
function currencyValid(currency) {
  //var filter1 = '/^\$?\d{1,3}(,?\d{3})*(\.\d{1,2})?$/' ;
  //var filter2 = '/^\$?\d{1.3}(.?\d{3})*(\,\d{1.2})?$/' ;
  //return filter1.test(currency) || filter2.test(currency); 
  return true;
}

 

function isInteger(num) {
  var i;
  var isInt = true;
  for (i = 0; i < num.length; i++) {
    if (!charIsDigit(num.substring(i,i+1)))
      isInt = false;
  }
  return isInt;
}


function FormFieldReader(form) {
  
  this.form       = form;
  this.formFields = new FormFields();
  
  this.getFormFields = function() {
    return this.formFields;
  }
  
  this.start = function() {
    this.processFields();
  }
  
  this.processFields = function() {
    for(var i = 0; i < this.form.length; i++) {
      this.processField(this.form[i]);
    }
  }
  
  this.processField = function(field) {
    switch(field.tagName) {
      case 'INPUT':    return this.processInputField(field);
      case 'TEXTAREA': return this.processTextAreaField(field);
      case 'SELECT':   return this.processSelectBox(field);
    }
  }
  
  this.processInputField = function(field) {
    switch(field.type) {
      case 'text':     return this.processTextTypeField(field);
      case 'password': return this.processPasswordField(field);
      case 'radio':    return this.processRadioButton(field);
      case 'checkbox': return this.processCheckBox(field);
      case 'hidden':   return this.processHiddenField(field);
    }
  }
  
  this.processTextAreaField = function(field) {
    var maximumLength = field.getAttribute('maxlength');

    if(maximumLength == '') {
      var field = new TextAreaField(field.tagName, 
                                    field.getAttribute('fullname'),
                                    field.value, 
                                    0, 
                                    field.getAttribute('required') == 'true',
                                    field.getAttribute('initial_value_type'),
                                    field.getAttribute('initial_value'));
    } else {
      var field = new TextAreaField(field.tagName, 
                                    field.getAttribute('fullname'),
                                    field.value, 
                                    maximumLength, 
                                    field.getAttribute('required') == 'true',
                                    field.getAttribute('initial_value_type'),
                                    field.getAttribute('initial_value'));
    }
    
    this.formFields.add(field);
  }
  
  this.processSelectBox = function(field) {
    var field = new SelectBox(field.tagName,
                              field.getAttribute('fullname'),
                              field.value, 
                              field.getAttribute('required') == 'true');
                              
    this.formFields.add(field);
  }
  
  this.processRadioButton = function(field) {
    var radioGroupIndex = this.formFields.locate(field.name);
    
    if(radioGroupIndex == FIELD_NOT_FOUND) {
      this.formFields.add(new RadioGroup(field.name, field.getAttribute('fullname')));
      radioGroupIndex = this.formFields.locate(field.name);
    }
    
    var radioGroup = this.formFields.get(radioGroupIndex);
    radioGroup.addItem(field.value, field.checked);
  }
  
  this.processHiddenField = function(field) {
    if(field.getAttribute('dataType') == 'checkbox_list') {
      var checkBoxListIndex = this.formFields.locate(field.name);
    
      if(checkBoxListIndex == FIELD_NOT_FOUND ) {
        this.formFields.add(new CheckBoxList(field.name, ''));
        checkBoxListIndex = this.formFields.locate(field.name);  
      }
    
      var checkBoxList = this.formFields.get(checkBoxListIndex);
      checkBoxList.setMinNrOfItems(field.getAttribute('checkedMin'));
      checkBoxList.setMaxNrOfItems(field.getAttribute('checkedMax'));
    }
  }
  
  this.processCheckBox = function(field) {
    if(field.getAttribute('checkboxList') != null && field.getAttribute('checkboxList') != '') {
      this.processCheckBoxItem(field);
    } else {
      this.processSingleCheckBox(field);
    }
  }
  
  this.processCheckBoxItem = function(field) {
    var checkBoxListIndex = this.formFields.locate(field.getAttribute('checkboxList'));
    
    if(!checkBoxListIndex) {
      this.formFields.add(new CheckBoxList(field.getAttribute('checkboxList')),
                                           field.getAttribute('fullname'));
      checkBoxListIndex = this.formFields.locate(field.getAttribute('checkboxList'));  
    }
    
    var checkBoxList = this.formFields.get(checkBoxListIndex);
    checkBoxList.addItem(field.name, field.checked);
    
    if(checkBoxList.getFullname() == '') {
      checkBoxList.setFullname(field.getAttribute('fullname'));
    }
  }
  
  this.processSingleCheckBox = function(field) {
    var field = new CheckBox(field.name,
                             field.getAttribute('fullname'),
                             field.checked,
                             field.getAttribute('required') == 'true');
    
    this.formFields.add(field);                             
  }
  
  this.processTextTypeField = function(field) {
    switch(field.getAttribute('dataType')) {
      case 'text':  return this.processTextField(field);
      case 'email': return this.processEmailField(field);
      case 'int':   return this.processNumberField(field);
      case 'date':  return this.processDateField(field);
    }
  }
  
  this.processPasswordField = function(field) {
    var field = new PasswordField(field.tagName, 
                                  field.getAttribute('fullname'), 
                                  field.value, 
                                  field.getAttribute('required') == 'true');
                                  
    this.formFields.add(field);
  }
  
  this.processTextField = function(field) {
    var field = new TextField(field.tagName,
                              field.getAttribute('fullname'), 
                              field.value, 
                              field.getAttribute('required') == 'true',
                              field.getAttribute('initial_value_type'),
                              field.getAttribute('initial_value'));
                              
    this.formFields.add(field);
  }
  
  this.processEmailField = function(field) {
    var field = new EmailField(field.name, 
                               field.getAttribute('fullname'),
                               field.value, 
                               field.getAttribute('required') == 'true',
                               field.getAttribute('initial_value_type'),
                               field.getAttribute('initial_value'));
    this.formFields.add(field);                            
  }
  
  this.processNumberField = function(field) {
    var field = new NumberField(field.name,
                                field.getAttribute('fullname'),
                                field.value,
                                field.getAttribute('required') == 'true',
                                field.getAttribute('initial_value_type'),
                                field.getAttribute('initial_value'));
    this.formFields.add(field);
  }
  
  this.processDateField = function(field) {
    var field = new DateField(field.name,
                              field.getAttribute('fullname'),
                              field.value,
                              field.getAttribute('required') == 'true',
                              field.getAttribute('initial_value_type'),
                              field.getAttribute('initial_value'));
                              
    this.formFields.add(field);
  }
}

function FormFields() {
  
  this.fields = new Array(0);
  
  this.add = function(formField) {
    this.fields.push(formField);
  }
  
  this.get = function(index) {
    return this.fields[index];
  }
  
  this.getResult = function() {
    var fieldResult;
    var result = FORM_RESULT_LEGAL;
     
    for(i = 0; i < this.getLength(); i++) {
      fieldResult = this.fields[i].getResult();
      
      if(fieldResult == FORM_RESULT_ILLEGAL) {
        return FORM_RESULT_ILLEGAL;
      } else if(fieldResult == FORM_RESULT_ADAPT) {
        fieldResult = FORM_RESULT_ADAPT;
      }
    }
    
    return fieldResult;
  }

  this.adaptFields = function() {
    for(i = 0; i < this.getLength(); i++) {
      if(this.isFieldAdaptable(this.fields[i]) && this.fields[i].needsAdapting()) {
        this.fields[i].clearValue();
      }
    }
  }
  
  this.isFieldAdaptable = function(field) {
    return field.tagName == "INPUT" ||
           field.tagName == "TEXTAREA";
  }

  this.getNrOfIllegalFields = function() {
    var illegalFieldCount = 0;
    
    for(i = 0; i < this.getLength(); i++) {
      if(this.fields[i].getResult() == FORM_RESULT_ILLEGAL) {
        illegalFieldCount++;
      }
    }
    
    return illegalFieldCount;
  }

  this.getLongestIllegalFieldNameLength = function() {
    var longestLength = 0;
    
    for(var i = 0; i < this.getLength(); i++) {
      if(this.fields[i].getResult() == FORM_RESULT_ILLEGAL) {
        var fieldName = this.fields[i].getFullname();
        
        if(fieldName.length > longestLength) {
          longestLength = fieldName.length;
        }
      }
    }
    
    return longestLength;
  }

  this.getLength = function() {
    return this.fields.length;
  }

  this.locate = function(name) {
    for(i = 0; i < this.getLength(); i++) {
      if(this.fields[i].getName() == name) {
        return i;
      }
    }
    
    return FIELD_NOT_FOUND;
  }

  this.getErrorMessage = function() {
    var errorNr         = 1;
    var message         = ERROR_MSG_HEADER + ':\n';
    
    for(i = 0; i < this.getLength(); i++) {
      if(this.fields[i].getResult() == FORM_RESULT_ILLEGAL) {
        message += errorNr++ + ') ' + 
                   this.fields[i].getFullname() + '    (' + 
                   this.fields[i].getErrorMessage() + ')\n';
      }
    }
    
    return message;
    
    return '';
  }

  this.getPaddingSpaces = function(nrOfSpaces) {
    var text = '';
    
    for(var i = 0; i < nrOfSpaces; i++) {
      text += ' ';
    }
    
    return text;
  }
}


function FormField(name, fullname, value, initialValueType, initialValue) {
  
  this.name             = name;
  this.fullname         = fullname;
  this.value            = value;
  this.initialValueType = initialValueType;
  this.initialValue     = initialValue;
  
  this.clearValue = function() {
    this.value = "";
  }
  
  this.getName = function() {
    return this.name;
  }
  
  this.getFullname = function() {
    return this.fullname;
  }
  
  this.getValue = function() {
    return this.value;
  }
  
  this.getInitialValueType = function() {
    return this.initialValueType;
  }
  
  this.getInitialValue = function() {
    return this.initialValue;
  }

  this.needsAdapting = function() {
    return this.initialValueType == VALUE_TYPE_INFORMATION &&
          !this.required && 
           this.value == this.initialValue;
  }
}

function TextField(name, fullname, value, required, initialValueType, initialValue) {
  
  this.name             = name;
  this.fullname         = fullname;
  this.value            = value;
  this.required         = required;
  this.initialValueType = initialValueType;
  this.initialValue     = initialValue;

  this.getResult = function() {
    if(this.initialValueType == VALUE_TYPE_DATA) {
      if(this.required) {
        if(this.value == "") {
          return FORM_RESULT_ILLEGAL;
        } else {
          return this.getTypeResult();
        }
      } else {
        return this.getTypeResult();
      }
    } else if(this.initialValueType == VALUE_TYPE_INFORMATION) {
      if(this.required) {
        if(this.value == this.initialValue) {
          return FORM_RESULT_ILLEGAL;
        } else {
          if(this.value == "") {
            return FORM_RESULT_ILLEGAL;
          } else {
            return this.getTypeResult();
          }
        }
      } else {
        if(this.value == this.initialValue) {
          return FORM_RESULT_ADAPT;
        } else {
          return this.getTypeResult();
        }
      }
    }
  }
  
  this.getTypeResult = function() {
    return FORM_RESULT_LEGAL;
  }
  
  this.getErrorMessage = function() {
    if(this.required && this.value == '') {
      return ERROR_MSG_REQUIRED;
    } else if (this.initialValueType == VALUE_TYPE_INFORMATION && this.value == this.initialValue) {
      return ERROR_MSG_VALUE_UNCHANGED;
    }
  }
}

TextField.prototype = new FormField;

function TextAreaField(name, fullname, value, maximumLength, required, initialValueType, initialValue) {
  
  this.name             = name;
  this.fullname         = fullname;
  this.value            = value;
  this.maximumLength    = maximumLength;
  this.required         = required;
  this.initialValueType = initialValueType;
  this.initialValue     = initialValue;
  
  this.getResult = function() {
    if(this.initialValueType == VALUE_TYPE_DATA) {
      if(this.required) {
        if(this.value == "") {
          return FORM_RESULT_ILLEGAL;
        } else {
          return this.getTypeResult();
        }
      } else {
        return this.getTypeResult();
      }
    } else if(this.initialValueType == VALUE_TYPE_INFORMATION) {
      if(this.required) {
        if(this.value == this.initialValue) {
          return FORM_RESULT_ILLEGAL;
        } else {
          if(this.value == "") {
            return FORM_RESULT_ILLEGAL;
          } else {
            return this.getTypeResult();
          }
        }
      } else {
        if(this.value == this.initialValue) {
          return FORM_RESULT_ADAPT;
        } else {
          return this.getTypeResult();
        }
      }
    }
  }
  
  this.getTypeResult = function() {
    if(this.maximumLength != null && this.value.length >= this.maximumLength) {
      return FORM_RESULT_ILLEGAL;
    } else {
      return FORM_RESULT_LEGAL;
    }
  }
  
  this.getErrorMessage = function() {
    if(this.required && this.value == '') {
      return ERROR_MSG_REQUIRED;
    } else if(this.maximumLength != null && this.value.length > this.maximumLength) {
      return formatErrorMessage(ERROR_MSG_LONG_TEXT, this.maximumLength);
    } else if(this.initialValueType == VALUE_TYPE_INFORMATION && this.value == this.initialValue) {
      return ERROR_MSG_VALUE_UNCHANGED;
    }
  }
}

TextAreaField.prototype = new FormField;

function NumberField(name, fullname, value, required, initialValueType, initialValue) {
  
  this.name             = name;
  this.fullname         = fullname;
  this.value            = value;
  this.required         = required;
  this.initialValueType = initialValueType;
  this.initialValue     = initialValue;
  
  this.getResult = function() {
    if(this.initialValueType == VALUE_TYPE_DATA) {
      if(this.required) {
        if(this.value == "") {
          return FORM_RESULT_ILLEGAL;
        } else {
          return this.getTypeResult();
        }
      } else {
        return this.getTypeResult();
      }
    } else if(this.initialValueType == VALUE_TYPE_INFORMATION) {
      if(this.required) {
        if(this.value == this.initialValue) {
          return FORM_RESULT_ILLEGAL;
        } else {
          if(this.value == "") {
            return FORM_RESULT_ILLEGAL;
          } else {
            return this.getTypeResult();
          }
        }
      } else {
        if(this.value == this.initialValue) {
          return FORM_RESULT_ADAPT;
        } else {
          return this.getTypeResult();
        }
      }
    }
  }
  
  this.getTypeResult = function() {
    var expression = /^-?[0-9]*$/
    
    if(!expression.test(this.value)) {
      return FORM_RESULT_ILLEGAL;
    }

    return FORM_RESULT_LEGAL;
  }
  
  this.getErrorMessage = function() {
    var expression = /^-?[0-9]*$/

    if(this.required && this.value == '') {
      return ERROR_MSG_REQUIRED;
    } else if(!expression.test(this.value)) {
      return ERROR_MSG_ILLEGAL_NUMBER;
    } else if(this.initialValueType == VALUE_TYPE_INFORMATION && this.value == this.initialValue) {
      return ERROR_MSG_VALUE_UNCHANGED;
    }
  }
}

NumberField.prototype = new FormField;

function EmailField(name, fullname, value, required, initialValueType, initialValue) {
  
  this.name             = name;
  this.fullname         = fullname;
  this.value            = value;
  this.required         = required;
  this.initialValueType = initialValueType;
  this.initialValue     = initialValue;
  
  this.getResult = function() {
    if(this.initialValueType == VALUE_TYPE_DATA) {
      if(this.required) {
        if(this.value == "") {
          return FORM_RESULT_ILLEGAL;
        } else {
          return this.getTypeResult();
        }
      } else {
        return this.getTypeResult();
      }
    } else if(this.initialValueType == VALUE_TYPE_INFORMATION) {
      if(this.required) {
        if(this.value == this.initialValue) {
          return FORM_RESULT_ILLEGAL;
        } else {
          if(this.value == "") {
            return FORM_RESULT_ILLEGAL;
          } else {
            return this.getTypeResult();
          }
        }
      } else {
        if(this.value == this.initialValue) {
          return FORM_RESULT_ADAPT;
        } else {
          return this.getTypeResult();
        }
      }
    }
  }
  
  this.getTypeResult = function() {
    var expression = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
    
    if(this.value == "") {
      return FORM_RESULT_LEGAL;
    }
    
    if(!expression.test(this.value)) {
      return FORM_RESULT_ILLEGAL;
    }

    return FORM_RESULT_LEGAL;
  }
  
  this.getErrorMessage = function() {
    var expression = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;

    if(this.required && this.value == '') {
      return ERROR_MSG_REQUIRED;
    } else if(this.initialValueType == VALUE_TYPE_INFORMATION && this.value == this.initialValue) {
      return ERROR_MSG_VALUE_UNCHANGED;
    } else if(!expression.test(this.value)) {
      return ERROR_MSG_ILLEGAL_EMAIL;
    }
  }
}

EmailField.prototype = new FormField;

function DateField(name, fullname, value, required, initialValueType, initialValue) {
  
  this.name             = name;
  this.fullname         = fullname;
  this.value            = value;
  this.required         = required;
  this.initialValueType = initialValueType;
  this.initialValue     = initialValue;
  
  this.getResult = function() {
    if(this.initialValueType == VALUE_TYPE_DATA) {
      if(this.required) {
        if(this.value == "") {
          return FORM_RESULT_ILLEGAL;
        } else {
          return this.getTypeResult();
        }
      } else {
        return this.getTypeResult();
      }
    } else if(this.initialValueType == VALUE_TYPE_INFORMATION) {
      if(this.required) {
        if(this.value == this.initialValue) {
          return FORM_RESULT_ILLEGAL;
        } else {
          if(this.value == "") {
            return FORM_RESULT_ILLEGAL;
          } else {
            return this.getTypeResult();
          }
        }
      } else {
        if(this.value == this.initialValue) {
          return FORM_RESULT_ADAPT;
        } else {
          return this.getTypeResult();
        }
      }
    }
  }
  
  this.getTypeResult = function() {
    var date = parseDate(this.value);
    
    if(this.value == "") {
      return FORM_RESULT_LEGAL;
    }
    
    if(date) {
      setHiddenDate(this.name, dateToISODate(date));
      return FORM_RESULT_LEGAL;
    }
    

    return FORM_RESULT_ILLEGAL;
  }
  
  this.getErrorMessage = function() {
    if(this.required && this.value == '') {
      return ERROR_MSG_REQUIRED;
    } else if(this.initialValueType == VALUE_TYPE_INFORMATION && this.value == this.initialValue) {
      return ERROR_MSG_VALUE_UNCHANGED;
    } else if(parseDate(this.value) == null) {
      return ERROR_MSG_ILLEGAL_DATE;
    }
  }
}

DateField.prototype = new FormField;

function PasswordField(name, fullname, value, required) {
  
  this.name          = name;
  this.fullname      = fullname;
  this.value         = value;
  this.required      = required;
  
  this.getResult = function() {
  	if(this.required && this.value == "") {
      return FORM_RESULT_ILLEGAL;
  	}
  	
  	return FORM_RESULT_LEGAL;
  }
  
  this.getErrorMessage = function() {
    if(this.required && this.value == '') {
      return ERROR_MSG_REQUIRED;
    }
  }
}

PasswordField.prototype = new FormField;

function SelectBox(name, fullname, value, required) {
  
  this.name     = name;
  this.fullname = fullname;
  this.value    = value;
  this.required = required;
  
  this.getResult = function() {
    if(this.required && this.value == "") {
      return FORM_RESULT_ILLEGAL;
    }
    
    return FORM_RESULT_LEGAL;
  }
  
  this.getErrorMessage = function() {
    if(this.required && this.value == '') {
      return ERROR_MSG_REQUIRED;
    }
  }
}

SelectBox.prototype = new FormField;

function RadioGroup(name, fullname) {
  
  this.name     = name;
  this.fullname = fullname;
  this.items    = new FieldItems();
  
  this.getName = function() {
    return this.name;
  }
  
  this.getFullname = function() {
    return this.fullname;
  }

  this.addItem = function(value, checked) {
    this.items.add(new RadioItem(value, checked));
  }
  
  this.getResult = function() {
    if(this.items.getCheckedItemsCount() == 1) {
      return FORM_RESULT_LEGAL;
    }
    
    return FORM_RESULT_ILLEGAL;
  }
  
  this.getErrorMessage = function() {
    if(this.items.getCheckedItemsCount() == 0) {
      return ERROR_MSG_REQUIRED;
    }
  }
}

function CheckBox(name, fullname, checked, required) {
  
  this.name     = name;
  this.fullname = fullname;
  this.checked  = checked;
  this.required = required;
  
  this.getResult = function() {
  	if(this.required && !this.checked) {
      return FORM_RESULT_ILLEGAL;
  	}
  	
  	return FORM_RESULT_LEGAL;
  }
  
  this.getErrorMessage = function() {
    if(this.required && !this.checked) {
      return ERROR_MSG_REQUIRED;
    }
  }
}

CheckBox.prototype = new FormField;

function CheckBoxList(name, fullname) {
  
  this.name     = name;
  this.fullname = fullname;
  this.items    = new FieldItems();
  
  this.getName = function() {
    return this.name;
  }
  
  this.setFullname = function(fullname) {
    this.fullname = fullname;
  }
  
  this.getFullname = function() {
    return this.fullname;
  }
  
  this.setMinNrOfItems = function(minNrOfItems) {
    this.minNrOfItems = minNrOfItems;
  }
  
  this.setMaxNrOfItems = function(maxNrOfItems) {
    this.maxNrOfItems = maxNrOfItems;
  }

  this.addItem = function(name, checked) {
    this.items.add(new CheckBoxItem(name, checked));
  }
  
  this.getResult = function() {
  	var checkedItemsCount = this.items.getCheckedItemsCount();
  	
  	if(checkedItemsCount < this.minNrOfItems || checkedItemsCount > this.maxNrOfItems) {
  	  return FORM_RESULT_ILLEGAL;
  	}

  	return FORM_RESULT_LEGAL;
  }
  
  this.getErrorMessage = function() {
    var checkedItemsCount = this.items.getCheckedItemsCount();
    
    if(checkedItemsCount < this.minNrOfItems) {
      return formatErrorMessage(ERROR_MSG_CHECKBOX_LIST_MIN, this.minNrOfItems);
    } else if(checkedItemsCount > this.maxNrOfItems) {
      return formatErrorMessage(ERROR_MSG_CHECKBOX_LIST_MAX, this.maxNrOfItems);
    }
  }
}

CheckBoxList.prototype = new FormField;

function FieldItems() {
  
  this.items = new Array();
  
  this.add = function(fieldItem) {
    this.items.push(fieldItem);
  }
  
  this.get = function(index) {
    return this.items[index];
  }
  
  this.getLength = function() {
    return this.items.length;
  }
  
  this.getCheckedItemsCount = function() {
    var checkedItemsCount = 0;

    for(var i = 0; i < this.getLength(); i++) {
      if(this.get(i).isChecked()) {
        checkedItemsCount++;
      }
    }
    
    return checkedItemsCount;
  }
}

function RadioItem(value, checked) {
  
  this.value   = value;
  this.checked = checked;
  
  this.getValue = function() {
    return this.value;
  }
  
  this.isChecked = function() {
    return this.checked;
  }
}

function CheckBoxItem(name, checked) {
  
  this.name    = name;
  this.checked = checked;
  
  this.getName = function() {
    return this.name;
  }
  
  this.isChecked = function() {
    return this.checked;
  }
}

function instanceOf(object, constructorFunction) {
  while(object != null) {
    if(object == constructorFunction.prototype) {
      return true;
    }
    
    object = object.__proto__;
  }
  
  return false;
}

function dateToISODate(date) {
  var year  = date.getFullYear();
  var month = date.getMonth() + 1;
  var day   = date.getDate();

  if(month < 10) {
    month = '0' + month;
  }
  
  if(day < 10) {
    day = '0' + day;
  }
    
  return year + '-' + month + '-' + day;
}

function setHiddenDate(name, date) {
  document.getElementById('hidden_' + name).value = date;
}

function formatErrorMessage(message, number) {
  return message.replace(/%d/, number);
}


// ===================================================================
// Author: Matt Kruse <matt@mattkruse.com>
// WWW: http://www.mattkruse.com/
//
// NOTICE: You may use this code for any purpose, commercial or
// private, without any further permission from the author. You may
// remove this notice from your final code if you wish, however it is
// appreciated by the author if at least my web site address is kept.
//
// You may *NOT* re-distribute this code in any way except through its
// use. That means, you can include it in your product, or your web
// site, or any other form where the code is actually being used. You
// may not put the plain javascript up on your site for download or
// include it in your javascript libraries for download. 
// If you wish to share this code with others, please just point them
// to the URL instead.
// Please DO NOT link directly to my .js files from your site. Copy
// the files to your server and use them there. Thank you.
// ===================================================================

// HISTORY
// ------------------------------------------------------------------
// March 11, 2003: Added parseDate() function
// March 11, 2003: Added "NNN" formatting option. Doesn't match up
//                 perfectly with SimpleDateFormat formats, but 
//                 backwards-compatability was required.

// ------------------------------------------------------------------
// These functions use the same 'format' strings as the 
// java.text.SimpleDateFormat class, with minor exceptions.
// The format string consists of the following abbreviations:
// 
// Field        | Full Form          | Short Form
// -------------+--------------------+-----------------------
// Year         | yyyy (4 digits)    | yy (2 digits), y (2 or 4 digits)
// Month        | MMM (name or abbr.)| MM (2 digits), M (1 or 2 digits)
//              | NNN (abbr.)        |
// Day of Month | dd (2 digits)      | d (1 or 2 digits)
// Day of Week  | EE (name)          | E (abbr)
// Hour (1-12)  | hh (2 digits)      | h (1 or 2 digits)
// Hour (0-23)  | HH (2 digits)      | H (1 or 2 digits)
// Hour (0-11)  | KK (2 digits)      | K (1 or 2 digits)
// Hour (1-24)  | kk (2 digits)      | k (1 or 2 digits)
// Minute       | mm (2 digits)      | m (1 or 2 digits)
// Second       | ss (2 digits)      | s (1 or 2 digits)
// AM/PM        | a                  |
//
// NOTE THE DIFFERENCE BETWEEN MM and mm! Month=MM, not mm!
// Examples:
//  "MMM d, y" matches: January 01, 2000
//                      Dec 1, 1900
//                      Nov 20, 00
//  "M/d/yy"   matches: 01/20/00
//                      9/2/00
//  "MMM dd, yyyy hh:mm:ssa" matches: "January 01, 2000 12:30:45AM"
// ------------------------------------------------------------------

var MONTH_NAMES=new Array('januari','februari','maart','april','mei','juni','juli','augustus','september','oktober','november','december','jan','feb','mar','apr','mei','jun','jul','aug','sep','okt','nov','dec');
var DAY_NAMES=new Array('zondag','maandag','dinsdag','woensdag','donderdag','vrijdag','zaterdag','zo','ma','di','wo','do','vr','za');
function LZ(x) {return(x<0||x>9?"":"0")+x}

// ------------------------------------------------------------------
// isDate ( date_string, format_string )
// Returns true if date string matches format of format string and
// is a valid date. Else returns false.
// It is recommended that you trim whitespace around the value before
// passing it to this function, as whitespace is NOT ignored!
// ------------------------------------------------------------------
function isDate(val,format) {
	var date=getDateFromFormat(val,format);
	if (date==0) { return false; }
	return true;
	}

// -------------------------------------------------------------------
// compareDates(date1,date1format,date2,date2format)
//   Compare two date strings to see which is greater.
//   Returns:
//   1 if date1 is greater than date2
//   0 if date2 is greater than date1 of if they are the same
//  -1 if either of the dates is in an invalid format
// -------------------------------------------------------------------
function compareDates(date1,dateformat1,date2,dateformat2) {
	var d1=getDateFromFormat(date1,dateformat1);
	var d2=getDateFromFormat(date2,dateformat2);
	if (d1==0 || d2==0) {
		return -1;
		}
	else if (d1 > d2) {
		return 1;
		}
	return 0;
	}

// ------------------------------------------------------------------
// formatDate (date_object, format)
// Returns a date in the output format specified.
// The format string uses the same abbreviations as in getDateFromFormat()
// ------------------------------------------------------------------
function formatDate(date,format) {
	format=format+"";
	var result="";
	var i_format=0;
	var c="";
	var token="";
	var y=date.getYear()+"";
	var M=date.getMonth()+1;
	var d=date.getDate();
	var E=date.getDay();
	var H=date.getHours();
	var m=date.getMinutes();
	var s=date.getSeconds();
	var yyyy,yy,MMM,MM,dd,hh,h,mm,ss,ampm,HH,H,KK,K,kk,k;
	// Convert real date parts into formatted versions
	var value=new Object();
	if (y.length < 4) {y=""+(y-0+1900);}
	value["y"]=""+y;
	value["yyyy"]=y;
	value["yy"]=y.substring(2,4);
	value["M"]=M;
	value["MM"]=LZ(M);
	value["MMM"]=MONTH_NAMES[M-1];
	value["NNN"]=MONTH_NAMES[M+11];
	value["d"]=d;
	value["dd"]=LZ(d);
	value["E"]=DAY_NAMES[E+7];
	value["EE"]=DAY_NAMES[E];
	value["H"]=H;
	value["HH"]=LZ(H);
	if (H==0){value["h"]=12;}
	else if (H>12){value["h"]=H-12;}
	else {value["h"]=H;}
	value["hh"]=LZ(value["h"]);
	if (H>11){value["K"]=H-12;} else {value["K"]=H;}
	value["k"]=H+1;
	value["KK"]=LZ(value["K"]);
	value["kk"]=LZ(value["k"]);
	if (H > 11) { value["a"]="PM"; }
	else { value["a"]="AM"; }
	value["m"]=m;
	value["mm"]=LZ(m);
	value["s"]=s;
	value["ss"]=LZ(s);
	while (i_format < format.length) {
		c=format.charAt(i_format);
		token="";
		while ((format.charAt(i_format)==c) && (i_format < format.length)) {
			token += format.charAt(i_format++);
			}
		if (value[token] != null) { result=result + value[token]; }
		else { result=result + token; }
		}
	return result;
	}
	
// ------------------------------------------------------------------
// Utility functions for parsing in getDateFromFormat()
// ------------------------------------------------------------------
function _isInteger(val) {
	var digits="1234567890";
	for (var i=0; i < val.length; i++) {
		if (digits.indexOf(val.charAt(i))==-1) { return false; }
		}
	return true;
	}
	
function _getInt(str,i,minlength,maxlength) {
	for (var x=maxlength; x>=minlength; x--) {
		var token=str.substring(i,i+x);
		if (token.length < minlength) { return null; }
		if (_isInteger(token)) { return token; }
		}
	return null;
	}
	
// ------------------------------------------------------------------
// getDateFromFormat( date_string , format_string )
//
// This function takes a date string and a format string. It matches
// If the date string matches the format string, it returns the 
// getTime() of the date. If it does not match, it returns 0.
// ------------------------------------------------------------------
function getDateFromFormat(val,format) {
	val=val+"";
	format=format+"";
	var i_val=0;
	var i_format=0;
	var c="";
	var token="";
	var token2="";
	var x,y;
	var now=new Date();
	var year=now.getYear();
	var month=now.getMonth()+1;
	var date=1;
	var hh=now.getHours();
	var mm=now.getMinutes();
	var ss=now.getSeconds();
	var ampm="";
	
	while (i_format < format.length) {
		// Get next token from format string
		c=format.charAt(i_format);
		token="";
		while ((format.charAt(i_format)==c) && (i_format < format.length)) {
			token += format.charAt(i_format++);
			}
		// Extract contents of value based on format token
		if (token=="yyyy" || token=="yy" || token=="y") {
			if (token=="yyyy") { x=4;y=4; }
			if (token=="yy")   { x=2;y=2; }
			if (token=="y")    { x=2;y=4; }
			year=_getInt(val,i_val,x,y);
			if (year==null) { return 0; }
			i_val += year.length;
			if (year.length==2) {
				if (year > 70) { year=1900+(year-0); }
				else { year=2000+(year-0); }
				}
			}
		else if (token=="MMM"||token=="NNN"){
			month=0;
			for (var i=0; i<MONTH_NAMES.length; i++) {
				var month_name=MONTH_NAMES[i];
				if (val.substring(i_val,i_val+month_name.length).toLowerCase()==month_name.toLowerCase()) {
					if (token=="MMM"||(token=="NNN"&&i>11)) {
						month=i+1;
						if (month>12) { month -= 12; }
						i_val += month_name.length;
						break;
						}
					}
				}
			if ((month < 1)||(month>12)){return 0;}
			}
		else if (token=="EE"||token=="E"){
			for (var i=0; i<DAY_NAMES.length; i++) {
				var day_name=DAY_NAMES[i];
				if (val.substring(i_val,i_val+day_name.length).toLowerCase()==day_name.toLowerCase()) {
					i_val += day_name.length;
					break;
					}
				}
			}
		else if (token=="MM"||token=="M") {
			month=_getInt(val,i_val,token.length,2);
			if(month==null||(month<1)||(month>12)){return 0;}
			i_val+=month.length;}
		else if (token=="dd"||token=="d") {
			date=_getInt(val,i_val,token.length,2);
			if(date==null||(date<1)||(date>31)){return 0;}
			i_val+=date.length;}
		else if (token=="hh"||token=="h") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<1)||(hh>12)){return 0;}
			i_val+=hh.length;}
		else if (token=="HH"||token=="H") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<0)||(hh>23)){return 0;}
			i_val+=hh.length;}
		else if (token=="KK"||token=="K") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<0)||(hh>11)){return 0;}
			i_val+=hh.length;}
		else if (token=="kk"||token=="k") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<1)||(hh>24)){return 0;}
			i_val+=hh.length;hh--;}
		else if (token=="mm"||token=="m") {
			mm=_getInt(val,i_val,token.length,2);
			if(mm==null||(mm<0)||(mm>59)){return 0;}
			i_val+=mm.length;}
		else if (token=="ss"||token=="s") {
			ss=_getInt(val,i_val,token.length,2);
			if(ss==null||(ss<0)||(ss>59)){return 0;}
			i_val+=ss.length;}
		else if (token=="a") {
			if (val.substring(i_val,i_val+2).toLowerCase()=="am") {ampm="AM";}
			else if (val.substring(i_val,i_val+2).toLowerCase()=="pm") {ampm="PM";}
			else {return 0;}
			i_val+=2;}
		else {
			if (val.substring(i_val,i_val+token.length)!=token) {return 0;}
			else {i_val+=token.length;}
			}
		}
	// If there are any trailing characters left in the value, it doesn't match
	if (i_val != val.length) { return 0; }
	// Is date valid for month?
	if (month==2) {
		// Check for leap year
		if ( ( (year%4==0)&&(year%100 != 0) ) || (year%400==0) ) { // leap year
			if (date > 29){ return 0; }
			}
		else { if (date > 28) { return 0; } }
		}
	if ((month==4)||(month==6)||(month==9)||(month==11)) {
		if (date > 30) { return 0; }
		}
	// Correct hours value
	if (hh<12 && ampm=="PM") { hh=hh-0+12; }
	else if (hh>11 && ampm=="AM") { hh-=12; }
	var newdate=new Date(year,month-1,date,hh,mm,ss);
	return newdate.getTime();
	}

// ------------------------------------------------------------------
// parseDate( date_string [, prefer_euro_format] )
//
// This function takes a date string and tries to match it to a
// number of possible date formats to get the value. It will try to
// match against the following international formats, in this order:
// y-M-d   MMM d, y   MMM d,y   y-MMM-d   d-MMM-y  MMM d
// M/d/y   M-d-y      M.d.y     MMM-d     M/d      M-d
// d/M/y   d-M-y      d.M.y     d-MMM     d/M      d-M
// A second argument may be passed to instruct the method to search
// for formats like d/M/y (european format) before M/d/y (American).
// Returns a Date object or null if no patterns match.
// ------------------------------------------------------------------
function parseDate(val) {
	var preferEuro=(arguments.length==2)?arguments[1]:false;
	//generalFormats=new Array('y-M-d','MMM d, y','MMM d,y','y-MMM-d','d-MMM-y','MMM d');
	//monthFirst=new Array('M/d/y','M-d-y','M.d.y','MMM-d','M/d','M-d');
	//dateFirst =new Array('d/M/y','d-M-y','d.M.y','d-MMM','d/M','d-M');
	val = replaceMonthsNL(val);
	generalFormats=new Array('d M y','d-M-y','d/M/y','d.M.y','d MMM y','d-MMM-y','d/MMM/y','d.MMM.y','MMM d, y' );

	//monthFirst=new Array('M/d/y','M-d-y','M.d.y','MMM-d','M/d','M-d',);
	//dateFirst =new Array('d/M/y','d-M-y','d.M.y','d-MMM','d/M','d-M');
  var checkList = new Array('generalFormats');
    
	//var checkList=new Array('generalFormats',preferEuro?'dateFirst':'monthFirst',preferEuro?'monthFirst':'dateFirst');
	var d=null;
	for (var i=0; i<checkList.length; i++) {
		var l=window[checkList[i]];
		for (var j=0; j<l.length; j++) {
			d=getDateFromFormat(val,l[j]);
			if (d>0) {
			  return new Date(d);
			} else if(d < 0) {
			  return new Date(d);
			}
	  }
  }
  
	return null;
}

function replaceMonthsNL(inDate) {
  var tempDate = inDate.toUpperCase();
  
  var re = new RegExp ('JANUARI', 'gi') ;
  tempDate=tempDate.replace(re,'JAN');

  var re = new RegExp ('FEBRUARI', 'gi') ;
  tempDate=tempDate.replace(re,'FEB');

  var re = new RegExp ('MAART', 'gi') ;
  tempDate=tempDate.replace(re,'MAR');

  var re = new RegExp ('MRT', 'gi') ;
  tempDate=tempDate.replace(re,'MAR');

  var re = new RegExp ('APRIL', 'gi') ;
  tempDate=tempDate.replace(re,'APR');

  var re = new RegExp ('MEI', 'gi') ;
  tempDate=tempDate.replace(re,'MAY');

  var re = new RegExp ('JUNI', 'gi') ;
  tempDate=tempDate.replace(re,'JUN');
  
  var re = new RegExp ('JULI', 'gi') ;
  tempDate=tempDate.replace(re,'JUL');

  var re = new RegExp ('AUGUSTUS', 'gi') ;
  tempDate=tempDate.replace(re,'AUG');

  var re = new RegExp ('SEPT', 'gi') ;
  tempDate=tempDate.replace(re,'SEP');

  var re = new RegExp ('SEPTEMBER', 'gi') ;
  tempDate=tempDate.replace(re,'JUN');
 
  var re = new RegExp ('OKT', 'gi') ;
  tempDate=tempDate.replace(re,'OCT');

  var re = new RegExp ('OKTOBER', 'gi') ;
  tempDate=tempDate.replace(re,'OCT');
  
  var re = new RegExp ('NOVEMBER', 'gi') ;
  tempDate=tempDate.replace(re,'NOV');
  
  var re = new RegExp ('DECEMBER', 'gi') ;
  tempDate=tempDate.replace(re,'DEC');
  
  var re = new RegExp (' +', 'gi') ;
  tempDate=tempDate.replace(re,' ');
  
  return tempDate.replace(/(^\s+)|(\s+$)/g, '');

}

function SCDate(year, month, day) {
  
  
}