n = (document.layers) ? 1:0
ie = (document.all) ? 1:0
if(n){var sichtbar="show", unsichtbar="hide"}
if(ie){var sichtbar="visible", unsichtbar="hidden"}

var prevpage='button00c'
var prevpos='top'
 function menuClicked(layername,position)
 {  if((position == 'top') && (prevpos == position)) {

		if(document.getElementById) { 
		myElement = document.getElementById(layername);
		myElement.style.visibility = 'visible'
		myElement = document.getElementById(prevpage);
		myElement.style.visibility = 'hidden' }

	if(n) { 
		document.layers[layername].visibility=sichtbar
		document.layers[prevpage].visibility=unsichtbar }
	if(ie) {
		document.all[layername].style.visibility=sichtbar
		document.all[prevpage].style.visibility=unsichtbar } }
   else if((position == 'bottom') && (prevpos == position)) {

		if(document.getElementById) { 
		myElement = document.getElementById(layername);
		myElement.style.visibility = 'visible'
		myElement = document.getElementById(prevpage);
		myElement.style.visibility = 'hidden' }

	if(n) { 
		parent.bottom[layername].visibility=sichtbar
		parent.bottom[prevpage].visibility=unsichtbar }
	if(ie) {
		parent.bottom[layername].style.visibility=sichtbar
		parent.bottom[prevpage].style.visibility=unsichtbar } }
   else if(position == 'bottom') {


		if(document.getElementById) { 
		myElement = document.getElementById(layername);
		myElement.style.visibility = 'visible'
		myElement = document.getElementById(prevpage);
		myElement.style.visibility = 'hidden' }

	if(n) { 
		parent.bottom[layername].visibility=sichtbar
		parent.headmenu[prevpage].visibility=unsichtbar }
	if(ie) {
		parent.bottom[layername].style.visibility=sichtbar
		parent.headmenu[prevpage].style.visibility=unsichtbar } }
   else {


		if(document.getElementById) { 
		myElement = document.getElementById(layername);
		myElement.style.visibility = 'visible'
		myElement = document.getElementById(prevpage);
		myElement.style.visibility = 'hidden' }

	if(n) { 
		parent.headmenu[layername].visibility=sichtbar
		parent.bottom[prevpage].visibility=unsichtbar }
	if(ie) {
		parent.headmenu[layername].style.visibility=sichtbar
		parent.bottom[prevpage].style.visibility=unsichtbar } }
	prevpage=layername
	prevpos=position
 }