/**
  * Main America_Ajax_Search_Filter_Settings Instance
  *
  * Ensures only one instance of asf_Settings is loaded or can be loaded.
  * 
  * @return Main America_Ajax_Search_Filter_Settings instance
  */
 public static function instance($parent)
 {
     if (is_null(self::$_instance)) {
         self::$_instance = new self($parent);
     }
     return self::$_instance;
 }
/**
 * Returns the main instance of aasf to prevent the need to use globals.
 *
 * @since  1.0.0
 * @return object America_Ajax_Search_Filter
 */
function america_ajax_search_filter()
{
    $instance = America_Ajax_Search_Filter::instance(__FILE__, '1.0');
    if (is_null($instance->settings)) {
        // TODO: create plugin settings screens
        $instance->settings = America_Ajax_Search_Filter_Settings::instance($instance);
    }
    return $instance;
}