gistfile1.txt

   //here it returns NULL 
                     global $wp_query, $wp_registered_sidebars, $wp_registered_widgets;
                     var_dump ($wp_registered_sidebars);

  $sidebar_contents = "";
	ob_start();
	dynamic_sidebar('top-util');
	$sidebar_contents = ob_get_contents();
	ob_end_clean();
	return $sidebar_contents;