Adding Administration Menus / Submenus

The example code for adding menus (http://codex.wordpress.org/Adding_Administration_Menus#Example) generates a nice batch of PHP errors.

Is there some sample code somewhere that works? Specifically, I’m trying to set up a custom Top Level menu with three submenus. I was able to do it with is_plugin_page() and files for each of the submenu pages (rendered with, e.g., admin.php?page=foo.php), but I’d prefer to be able to render them directly from individual files (e.g. foo.php) or from functions in the top-level menu page.

Thanks!