/* Handhabung des pop-up-Menüs, wird zu jeder Seite hinzugefügt */

 var old = "b";
 var old2="a";
 var memold ="";

 function show_layer(x)
 {
	if(document.all)
		document.all[x].style.visibility="visible";
	else if(document.layers)
		document.layers[x].visibility="show";
	else
		{
		document.getElementById(x).style.visibility="visible";
		}
 }

 function hide_layer(x)
 {
	if(document.all)
		document.all[x].style.visibility="hidden";
	else if(document.layers)
		document.layers[x].visibility="hide"; 
	else
		document.getElementById(x).style.visibility="hidden";
 } 

 function do_check(x)
 {
	if(old && old!=x)
	{
		hide_layer(old);
		show_layer(x);
		old=x;
	}
 }

 function do_check2(x)
 {
	if(old2 && old2!=x)
	{
		hide_layer(old2);
		show_layer(x);
		old2=x;
	}
 } 


 function do_menu(x)
 {
	if(!old) old=memold;
	if(old!=x)
	{
		show_layer(x);
		old=x;
	} else
		old="";
 }