function klapp(zap) {
			if (document.getElementById) {
				var abra = document.getElementById(zap).style;
				var pat = document.getElementById('patienteninfo').style;
				var str = document.getElementById('struktur').style;
  				window.status = zap;
				if (abra.display == "block") {
					abra.display = "none";
					} else {
						abra.display = "block";
						if (zap == 'struktur') {pat.display = "none";}
						if (zap == 'patienteninfo') {str.display = "none";}
						}
				return false
				} else {
				return true
				}
			}