If you want to make it act like an accordion, you can do like this:
$('.main').click(function() {
$(this).toggleClass("main remove").find('.submenu').slideToggle(400);
$(this).closest('li').siblings('.main').find('.submenu').slideUp(400);
})
I think you don't need to slideUp the other .main
when one .main
clicked, so just use:
$('.main').click(function() {
$(this).toggleClass("main remove").find('.submenu').slideToggle(400);
})