/**
  * Updates configuration with values from form elements.
  */
 public function updateModel($config)
 {
     foreach ($this->_options as $name => $option) {
         $value = $this->getElement($name)->getValue();
         // TODO move into Admin_Model_Option?
         if (is_array($value)) {
             $value = implode(',', $value);
         }
         Application_Configuration::setValueInConfig($config, $option->getKey(), $value);
     }
 }