function getUserAgent(){
  if(window.sidebar){ return "FF";}
  else if(window.external){return"IE";}
  else if(window.opera){return"Opera";}
  else{return"unknown";}
}
function addBookmark(hrefUrl,hrefTitle){
  if(getUserAgent()=='IE'){window.external.AddFavorite(hrefUrl,hrefTitle);}
  else if(getUserAgent()=='FF'){window.sidebar.addPanel(hrefTitle,hrefUrl,"");}
  else {/* nepodporovany prohlizec */}
}