var opened = false;
$('mainmenu_switch').addEvent("click", function(e){
	new Event(e).stop();
	//ef.toggle();
	
	$('mainmenu_switch').innerHTML = (!opened) ? '<span>Navigation verbergen</span>': '<span>Navigation anzeigen</span>';
	opened = !opened; 
	switchNavi(opened);
});


function switchNavi(open) {
	if(open) $$('#mainmenu li.parent').addClass('open');
	else $$('#mainmenu li.parent').removeClass('open');
}