function schovej() {

   if (navigator.appName != "Microsoft Internet Explorer") return

   var s = document.getElementsByTagName("SELECT");
   for (var i=0; i< s.length;i++) {
     var ss=s[i];
     ss.style.visibility="hidden";
   }
}


function ukaz() {
  if (navigator.appName != "Microsoft Internet Explorer") return

  var s = document.getElementsByTagName("SELECT");
  for (var i=0; i< s.length;i++) {
    var ss=s[i];
    ss.style.visibility="visible";
  }
}