static function pf_toplevelpage( &$parser /* , $title = null */ ) {		
		$t = self::newTitleObject( $parser, func_get_args() );
		if( $t === null ) {
			return ''; // invalid title given
		}
		
		//get all parents because the toplevel is the highest existing parent:
		$parentpages = SubpageInfo::getAncestorPages( $t );
		
		if( ! empty( $parentpages ) ) {
			return wfEscapeWikiText( $parentpages[0]->getPrefixedText() );
		}
		else {
			////no parent! The page itself is the top level:
			return wfEscapeWikiText( $t->getPrefixedText() );
		}
	}
	/**
	 * Delivers the real subpage title, not only the part behind the last "/" like PAGENAME does.
	 * 
	 * @param Title $page The page to get the title from.
	 * 
	 * @return string Result The subpage title of the given page. If page isn't a subpage, the Pages
	 *                name (without prefix) will be returned.
	 */
	static function getSubpageTitle( Title $page ) {
		$parent = SubpageInfo::getParentPage( $page );
		//return the whole subpage name not like SUBPAGENAME only the last part after the last "/":
		if( ! empty( $parent ) ) {
			return substr( $page->getText(), strlen( $parent->getText() . '/' ) );
		}
		return $page->getText(); //return PAGENAME
	}