function clean ()
{
  if ((navigator.appName=='Netscape') && (navigator.appVersion.charAt (0)<'5'))
  {
  window.document.b.visibility="hide";
  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";
  window.document.m6.visibility="hide";  
  return;
  }
 if (navigator.appVersion.charAt (0)<'5')
    {
    var layers=document.all.tags ("div");
    }
    else {
    var layers=document.getElementsByTagName("div");
    }
 layers[0].style.visibility='hidden';
 layers[2].style.visibility='hidden';
 layers[4].style.visibility='hidden';
 layers[6].style.visibility='hidden';
 layers[8].style.visibility='hidden';
 layers[10].style.visibility='hidden';
 layers[12].style.visibility='hidden'; 
 return;
}

function menu (i)
{

switch(i)
 {
  case 1:
   {
    if ((navigator.appName=='Netscape') && (navigator.appVersion.charAt(0)<'5'))
     {
      window.document.b.visibility="show";
      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";
      window.document.m6.visibility="hide";      
     return;
     }
    if (navigator.appVersion.charAt (0)<'5')
    {
    var layers=document.all.tags ("div");
    }
    else {
    var layers=document.getElementsByTagName("div");
    }
    layers[0].style.visibility='visible';
    layers[2].style.visibility='visible';
    layers[4].style.visibility='hidden';
    layers[6].style.visibility='hidden';
    layers[8].style.visibility='hidden';
    layers[10].style.visibility='hidden';
    layers[12].style.visibility='hidden';    
    return;
   }
  case 2:
   {
    if ((navigator.appName=='Netscape') && (navigator.appVersion.charAt(0)<'5'))
     {
     window.document.b.visibility="show";
     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";
     window.document.m6.visibility="hide";     
     return;
     }
    if (navigator.appVersion.charAt (0)<'5')
    {
    var layers=document.all.tags ("div");
    }
    else {
    var layers=document.getElementsByTagName("div");
    }
    layers[0].style.visibility='visible';
    layers[2].style.visibility='hidden';
    layers[4].style.visibility='visible';
    layers[6].style.visibility='hidden';
    layers[8].style.visibility='hidden';
    layers[10].style.visibility='hidden';
    layers[12].style.visibility='hidden';    
    return;
   }
  case 3:
   {
    if ((navigator.appName=='Netscape') && (navigator.appVersion.charAt(0)<'5'))
     {
     window.document.b.visibility="show";
     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";
     window.document.m6.visibility="hide";     
     return;
     }
    if (navigator.appVersion.charAt (0)<'5')
    {
    var layers=document.all.tags ("div");
    }
    else {
    var layers=document.getElementsByTagName("div");
    }
    layers[0].style.visibility='visible';
    layers[2].style.visibility='hidden';
    layers[4].style.visibility='hidden';
    layers[6].style.visibility='visible';
    layers[8].style.visibility='hidden';
    layers[10].style.visibility='hidden';
    layers[12].style.visibility='hidden';
    return;
   }

  case 4:
   {
    if ((navigator.appName=='Netscape') && (navigator.appVersion.charAt(0)<'5'))
     {
     window.document.b.visibility="show";
     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";
     window.document.m6.visibility="hide";     
     return;
     }
    if (navigator.appVersion.charAt (0)<'5')
    {
    var layers=document.all.tags ("div");
    }
    else {
    var layers=document.getElementsByTagName("div");
    }
    layers[0].style.visibility='visible';
    layers[2].style.visibility='hidden';
    layers[4].style.visibility='hidden';
    layers[6].style.visibility='hidden';
    layers[8].style.visibility='visible';
    layers[10].style.visibility='hidden';
    layers[12].style.visibility='hidden';    
    return;
   }   
   
  case 5:
   {
    if ((navigator.appName=='Netscape') && (navigator.appVersion.charAt(0)<'5'))
     {
     window.document.b.visibility="show";
     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";
     window.document.m6.visibility="hide";     
     return;
     }
    if (navigator.appVersion.charAt (0)<'5')
    {
    var layers=document.all.tags ("div");
    }
    else {
    var layers=document.getElementsByTagName("div");
    }
    layers[0].style.visibility='visible';
    layers[2].style.visibility='hidden';
    layers[4].style.visibility='hidden';
    layers[6].style.visibility='hidden';
    layers[8].style.visibility='hidden';
    layers[10].style.visibility='visible';
    layers[12].style.visibility='hidden'; 
    return;
   } 
   
  case 6:
   {
    if ((navigator.appName=='Netscape') && (navigator.appVersion.charAt(0)<'5'))
     {
     window.document.b.visibility="show";
     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";
     window.document.m6.visibility="show";     
     return;
     }
    if (navigator.appVersion.charAt (0)<'5')
    {
    var layers=document.all.tags ("div");
    }
    else {
    var layers=document.getElementsByTagName("div");
    }
    layers[0].style.visibility='visible';
    layers[2].style.visibility='hidden';
    layers[4].style.visibility='hidden';
    layers[6].style.visibility='hidden';
    layers[8].style.visibility='hidden';
    layers[10].style.visibility='hidden';
    layers[12].style.visibility='visible'; 
    return;
   }  
   
 }

}