window.addEvent('domready' , function(){
	var sidebar = document.getElement('#sidebar');
	var top_level = sidebar.getElements('.top-level');
	top_level.setStyles({
		'display' : 'block',
		'cursor'  : 'pointer'
	});
	var parts = sidebar.getElements('.part');
	parts.each(function(e){
		if (e.getElements('.active').length == 0) e.setStyle('display' , 'none');
	});
	top_level.addEvent('click' , function(){
		var sub = this.getNext('.part'),
      display = sub.getStyle('display');
    document.getElements('#sidebar .part').setStyle('display' , 'none');
		sub.setStyle('display' , display == 'none' ? 'block' : 'none');
	});
});