protected function prepareFieldsetNavigation()
{
$fldNav = $this->_form->addFieldset('navigation', array('legend' => $this->__('Layered Navigation')));
$note = new Varien_Data_Form_Element_Note(array('text' => $this->__('Please set filter display type to <b>Images only</b> or <b>Images and labels</b> in order to make these settings work.')));
$note->setId('layered_navigation_note');
$fldNav->addElement($note);
$fldNav->addField('img_small', 'file', array('label' => $this->__('Image'), 'name' => 'img_small', 'required' => false, 'after_element_html' => $this->getImageHtml($this->model->getImgSmall())));
$fldNav->addField('remove_img_small', 'checkbox', array('label' => $this->__('Remove Image'), 'name' => 'remove_img_small', 'value' => 1));
$fldNav->addField('img_small_hover', 'file', array('label' => $this->__('Active & Hover Image'), 'name' => 'img_small_hover', 'required' => false, 'after_element_html' => $this->getImageHtml($this->model->getImgSmallHover())));
$fldNav->addField('remove_img_small_hover', 'checkbox', array('label' => $this->__('Remove Image'), 'name' => 'remove_img_small_hover', 'value' => 1));
}