/**
  * @see Form::validate()
  */
 public function validate()
 {
     parent::validate();
     if ($this->action == 'modify') {
         if (empty($_POST['menuItem'])) {
             throw new UserInputException('menuItem', 'empty');
         } else {
             if (empty($_POST['menuItemLink'])) {
                 throw new UserInputException('menuItemLink', 'empty');
             } else {
                 if (!empty($_POST['showOrder']) && !preg_match('/^\\d+$/', $_POST['showOrder'])) {
                     throw new UserInputException('showOrder', 'empty');
                 } else {
                     if (!AdminTools::validateLinkExists($this->menuItemID, $this->linkCur['menuItem'])) {
                         throw new UserInputException('menuItem', 'exists');
                     }
                 }
             }
         }
     }
 }