Making my own module

Dear all,

I’ve been trying to fabricate my own plugin, but I can’t seem to find out how to add a submenu page to a menu_page. Any hints and tricks for this newbie, is very much appreciated!

Here’s my code:

function e_academy_pages() {
add_menu_page('E-Academy', 'E-Academy', 3, __FILE__, 'e_academy_hoofdpagina', '', 40);
add_submenu_page('E-Academy', 'Nieuws', 'Nieuws', 3, 'nieuws', 'e_academy_nieuws');
add_submenu_page('Procedures', 'Procedures', 1, __FILE__, 'e_academy_procedures');
add_submenu_page('Nieuw item', 'Nieuw item', 9, __FILE__, 'e_academy_nieuw');
add_submenu_page('Wijzigen', 'Wijzigen', 9, __FILE__, 'e_academy_wijzigen');
}

Thanks a lot!

Casper