function switchMenu(obj) {
	var el = document.getElementById(obj);
	if ( el.style.display != "none" ) {
		el.style.display = 'none';
	}
	else {
		el.style.display = '';
	}
}

function driedicht(obj1,obj2,obj3) {
   var el = document.getElementById(obj1);
   el.style.display='none';
   var el = document.getElementById(obj2);
   el.style.display='none';
   var el = document.getElementById(obj3);
   el.style.display='none';
}

function vierdicht(obj1,obj2,obj3, obj4) {
   var el = document.getElementById(obj1);
   el.style.display='none';
   var el = document.getElementById(obj2);
   el.style.display='none';
   var el = document.getElementById(obj3);
   el.style.display='none';
   var el = document.getElementById(obj4);
   el.style.display='none';
}