function showhide(item,state) {
  var browser = navigator.appName;
  if (browser == 'Microsoft Internet Explorer') {
  eval("document.all." + item + ".style.visibility ='" + state + "'");
  };
  if (browser == 'Netscape') {
    var drop_menu = document.getElementById(item);
    var show_hide = state;
    drop_menu.style.visibility = show_hide;
  };
}