document.observe("dom:loaded", function() {
	$$('.side_menu .side_menu_option').each(function(item) {
		item.observe('click', function(event) {
			this.siblings().invoke('removeClassName', 'selected');
			this.addClassName('selected');
			
			var toShow = this.up('tr').down('.right_column div.'+this.readAttribute('content_class'));
			toShow.siblings().invoke('hide');
			toShow.show();
		});
	});
});