function menu_changestate(id,host) {
  ico=document.getElementById('menu_ikona_'+id);
  men=document.getElementById('menu_volby_'+id);
  if (ico&&men) {
    if (men.style.display=='block') {
      men.style.display='none';
      ico.style.backgroundImage="url("+host+"img/plus.gif)";
      ico.style.backgroundColor="#ECF6D9";
    } else {
      men.style.display='block';
      ico.style.backgroundImage="url("+host+"img/minus.gif)";
      ico.style.backgroundColor="#ABDA50";
    }
  }
  return(false);
}