/**
  * Back-end widget form.
  *
  * @see WP_Widget::form()
  *
  * @param array $instance Previously saved values from database.
  */
 public function form($instance)
 {
     $this->display_title(empty($instance['title']) ? '' : $instance['title']);
     $this->display_href(empty($instance['href']) ? '' : $instance['href']);
     if (!class_exists('Facebook_Like_Button_Settings')) {
         require_once dirname(dirname(dirname(__FILE__))) . '/admin/settings-like-button.php';
     }
     $like_button_settings = new Facebook_Like_Button_Settings($instance);
     echo '<div>';
     $like_button_settings->display_send(array('id' => $this->get_field_id('send'), 'name' => $this->get_field_name('send')));
     echo '</div><p></p>';
     echo '<div>' . esc_html(__('Layout', 'facebook')) . ': ';
     $like_button_settings->display_layout(array('id' => $this->get_field_id('layout'), 'name' => $this->get_field_name('layout')));
     echo '</div><p></p>';
     echo '<div>';
     $like_button_settings->display_show_faces(array('id' => $this->get_field_id('show_faces'), 'name' => $this->get_field_name('show_faces')));
     echo '</div><p></p>';
     echo '<div><label for="' . $this->get_field_id('width') . '">' . esc_html(__('Width', 'facebook')) . '</label>: ';
     $like_button_settings->display_width(array('id' => $this->get_field_id('width'), 'name' => $this->get_field_name('width')));
     echo '</div><p></p>';
     echo '<div>' . esc_html(__('Action', 'facebook')) . ': ';
     $like_button_settings->display_action(array('id' => $this->get_field_id('action'), 'name' => $this->get_field_name('action')));
     echo '</div><p></p>';
     echo '<div><label for="' . $this->get_field_id('font') . '">' . esc_html(__('Font', 'facebook')) . '</label>: ';
     $like_button_settings->display_font(array('id' => $this->get_field_id('font'), 'name' => $this->get_field_name('font')));
     echo '</div><p></p>';
     echo '<div style="line-height:2em">' . esc_html(__('Color scheme', 'facebook')) . ': ';
     $like_button_settings->display_colorscheme(array('id' => $this->get_field_id('colorscheme'), 'name' => $this->get_field_name('colorscheme')));
     echo '</div>';
 }