WordPress Short code for List style

I finally make it ready after some more research.

function coregnie_list_ul( $atts, $content = null ) {

extract(shortcode_atts(array(
  'style' => 'cg_list',
), $atts));

return '<ul class=cg_list_'.$style.' >'.do_shortcode($content).'</ul>';
}
add_shortcode('ul', 'coregnie_list_ul');

function coregnie_list_li( $atts, $content = null ) {
return '<li>'.do_shortcode($content).'</li>';
}
add_shortcode('li', 'coregnie_list_li');