function show (co)
{
  if(document.getElementById(co).style.display == "none")
    document.getElementById(co).style.display="block";
  else
    document.getElementById(co).style.display="none";          
}

function show_hide_hledani()
{  
  selected = document.getElementById("tabulka").options[document.getElementById("tabulka").selectedIndex].value;    
  
  document.getElementById("autori").style.display = "none";
  document.getElementById("knihy").style.display = "none";
  document.getElementById("recenze").style.display = "none";
      
  
  if(selected == "autori" || (!selected))
    document.getElementById("autori").style.display = "block";
  else
  if(selected == "knihy")
    document.getElementById("knihy").style.display = "block";
  else  
  if(selected == "recenze")
    document.getElementById("recenze").style.display = "block";                           
}

function show_zanr (co)
{
  self.location='http://www.knihovnicka.net/kniha/zanry-kategorie/?zanr='+co;          
}

function md5form(f) {
  f['password_hmac'].value = hex_hmac_md5(hex_md5(f['heslo'].value), f['challenge'].value);     
  f['heslo'].disabled = true;     
  f.submit(); 
  f['heslo'].disabled = false;
  return false; 
}

function select(obj) {


  if (obj.className == 'tab_zprava') {
    obj.className = 'tab_zprava_selected';
  }
  else {
    obj.className = 'tab_zprava';
  }
}

function unselect(obj) {
    obj.className = 'tab_zprava';
}

function click(obj) {
  self.location=obj;
}