File attachment shortcode

// http://www.gravityhelp.com/forums/topic/extract-file-upload-name-in-email-notification
// shortcode usage: [gf_filename]{MERGE TAG}[/gf_filename]
// if you want an HTML link, you can do this:
// <a href="{MERGE TAG}" title="click to view">[gf_filename]{MERGE TAG}[/gf_filename]</a>
add_shortcode ('gf_filename', 'uploaded_file_basename');
function uploaded_file_basename( $atts, $content = null ) {
        $filename = basename($content);
        return $filename;
}