$(function(){
	// add class to elements containing collapsable items
	$('.collapsable').each(function(index, el) {
		$(el).slideToggle().parents('li').addClass('closed');
	});
	// remove class if present or add it + toggle collapsable
	$('.collapse').each(function(index, el) {	
		$(el).click(function(event) {
			event.preventDefault();
			var li = $(el).parents('li').first();
			if( li.hasClass('closed') ) li.removeClass('closed');
			else li.addClass('closed');
			$(el).siblings('.collapsable').first().slideToggle();
		});
	});
});