var ns4 = (document.layers) ? true : false;
var ie4 = (document.all) ? true : false;
var help1=document.location.href.split('/');
var gruppe=help1[help1.length-2];
var LastShown = "";
var LastShownDot = "";

about2 = new Image();
about2.src = "about2.gif";

function DisSub(ID) {
	HideSub();
	if (ns4) {
		css = document.layers[ID];
		}
	if (ie4) {
		css = document.all[ID].style;
		}
	css.visibility = "visible";
	LastShown = ID;
}

function HideSub() {
	HideDot();
	if (LastShown != "") {
		if (ns4) {
			css = document.layers[LastShown];
			}
		if (ie4) {
			css = document.all[LastShown].style;
		}
	css.visibility = "hidden";
	LastShown = "";
	}
}

function ShowSub(ID) {
	if (ns4) {
		css = document.layers[ID];
		}
	if (ie4) {
		css = document.all[ID].style;
		}
	css.visibility = "visible";
	LastShown = ID;
}

function DisDot(ID) {
	HideDot();
	if (ns4) {
		document.layers[LastShown].document.images[ID].src = ("Images/dot_rood.gif");
		}
	if (ie4) {
		document[ID].src = ("Images/dot_rood.gif");
		}
	LastShownDot = ID;
}

function HideDot() {
	if (LastShownDot != "") {
		if (ns4) {
			document.layers[LastShown].document.images[LastShownDot].src = ("Images/transparent.gif");
			}
		if (ie4) {
			document[LastShownDot].src = ("Images/transparent.gif");
			}
	LastShownDot = "";
	}
}
<!--
function MM_swapImgRestore() { //v3.0
  var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}

function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}

function MM_findObj(n, d) { //v4.0
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && document.getElementById) x=document.getElementById(n); return x;
}

function MM_swapImage() { //v3.0
  var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
   if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}