var alt = 0;
function checksub (i)
{
if (alt == i)
  {
   clean();
  }
else
  {
   menu(i);
   alt = i;
  }
}



function menu (i)
{
switch(i)
 {
  case 1:
   {
    if ((navigator.appName=='Netscape') && (navigator.appVersion.charAt(0)<'5'))
     {
     	window.document.m1.visibility="show";
     	window.document.m2.visibility="hide";
     	window.document.m3.visibility="hide";
     	window.document.m4.visibility="hide";
	window.document.m5.visibility="hide";
     	return;
     }
    if (navigator.appVersion.charAt (0)<'5')
    {
    var layers=document.all.tags ("table");
    }
    else {
    var layers=document.getElementsByTagName("table");
    }
    	layers[1].style.visibility='visible'; 
    	layers[2].style.visibility='hidden';
    	layers[3].style.visibility='hidden';
    	layers[4].style.visibility='hidden';
    	layers[5].style.visibility='hidden';
    	return;
   }
  
  case 2:
   {
    if ((navigator.appName=='Netscape') && (navigator.appVersion.charAt(0)<'5'))
     {
      window.document.m1.visibility="hide";
      window.document.m2.visibility="show";
      window.document.m3.visibility="hide";
      window.document.m4.visibility="hide";
      window.document.m5.visibility="hide";
     return;
     }
    if (navigator.appVersion.charAt (0)<'5')
    {
    var layers=document.all.tags ("table");
    }
    else {
    var layers=document.getElementsByTagName("table");
    }
    layers[1].style.visibility='hidden'; 
    layers[2].style.visibility='visible';
    layers[3].style.visibility='hidden';
    layers[4].style.visibility='hidden';
    layers[5].style.visibility='hidden';
    return;
   }
 
  case 3:
   {
    if ((navigator.appName=='Netscape') && (navigator.appVersion.charAt(0)<'5'))
     {
      window.document.m1.visibility="hide";
      window.document.m2.visibility="hide";
      window.document.m3.visibility="show"; 
      window.document.m4.visibility="hide";
      window.document.m5.visibility="hide";
     return;
     }
    if (navigator.appVersion.charAt (0)<'5')
    {
    var layers=document.all.tags ("table");
    }
    else {
    var layers=document.getElementsByTagName("table");
    }
    layers[1].style.visibility='hidden'; 
    layers[2].style.visibility='hidden';
    layers[3].style.visibility='visible';
    layers[4].style.visibility='hidden';
    layers[5].style.visibility='hidden';
    return;
   }
   
  case 4:
   {
    if ((navigator.appName=='Netscape') && (navigator.appVersion.charAt(0)<'5'))
     {
      window.document.m1.visibility="hide";
      window.document.m2.visibility="hide";
      window.document.m3.visibility="hide"; 
      window.document.m4.visibility="show";
      window.document.m5.visibility="hide";
     return;
     }
    if (navigator.appVersion.charAt (0)<'5')
    {
    var layers=document.all.tags ("table");
    }
    else {
    var layers=document.getElementsByTagName("table");
    }
    layers[1].style.visibility='hidden'; 
    layers[2].style.visibility='hidden';
    layers[3].style.visibility='hidden';
    layers[4].style.visibility='visible';
    layers[5].style.visibility='hidden';
    return;
   }   

  case 5:
   {
    if ((navigator.appName=='Netscape') && (navigator.appVersion.charAt(0)<'5'))
     {
      window.document.m1.visibility="hide";
      window.document.m2.visibility="hide";
      window.document.m3.visibility="hide"; 
      window.document.m4.visibility="hide";
      window.document.m5.visibility="show";
     return;
     }
    if (navigator.appVersion.charAt (0)<'5')
    {
    var layers=document.all.tags ("table");
    }
    else {
    var layers=document.getElementsByTagName("table");
    }
    layers[1].style.visibility='hidden'; 
    layers[2].style.visibility='hidden';
    layers[3].style.visibility='hidden';
    layers[4].style.visibility='hidden';
    layers[5].style.visibility='visible';
    return;
   }   

   
 }
}


function clean ()
{
alt = 0;
  if ((navigator.appName=='Netscape') && (navigator.appVersion.charAt (0)<'5'))
  {
  window.document.m1.visibility="hide";
  window.document.m2.visibility="hide";
  window.document.m3.visibility="hide";
  window.document.m4.visibility="hide";
  window.document.m5.visibility="hide";
  return;
  }
 if (navigator.appVersion.charAt (0)<'5')
    {
    var layers=document.all.tags ("table");
    }
    else {
    var layers=document.getElementsByTagName("table");
    }
 layers[1].style.visibility='hidden'; 
 layers[2].style.visibility='hidden';
 layers[3].style.visibility='hidden';
 layers[4].style.visibility='hidden';
 layers[5].style.visibility='hidden';
 return;
}


function PopUp()
{
	var URL = "grusswort.html";
	var Name = "popup";
	var x = 250;
	var y = 250;
	var Fensteroptionen = "toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=0";
	var Breite = 525;
	var Hoehe = 450;
	window.open(URL, 'Name', Fensteroptionen + ',width=' + Breite + ',height=' + Hoehe + ',screenX=' + x + ',screenY=' + y);
}