locate_skin_url()

gistfile1.php

<?php

function locate_skin_url( $name ) {
	$dir = false === strpos($name, '.css') ? 'js' : 'css';

	if ( file_exists(STYLESHEETPATH . "/$dir/$name")) {
		$url = get_bloginfo('stylesheet_directory') . "/$dir/$name";
	} elseif ( file_exists(TEMPLATEPATH . "/$dir/$name") ) {
		$url = get_bloginfo('template_directory') . "/$dir/$name";
	} else {
		$url = '';
	}

	return $url;
}