function ztmavit(navigace,akce) {
if (navigator.appName.indexOf("Netscape") != -1 && parseInt(navigator.appVersion) >= 5)
    {
      if (akce == 0)
        navigace.style.MozOpacity = .8;
      else
        navigace.style.MozOpacity = 1;
    }
  else
    {
      if (akce == 0)
        navigace.filters.alpha.opacity = 80;   
      else
        navigace.filters.alpha.opacity = 100;
    }
}