function pocet(textpole,znaku,max_znaku_txt,znaku_txt){
  poc = textpole.value.length;
  zbyva = znaku - poc;
  id_txt = textpole.id;
  if (zbyva <= 0) zbyva = 0;
  document.getElementById('info_'+id_txt).innerHTML = zbyva;
  if(poc >= znaku){
    window.alert(max_znaku_txt+" "+znaku+" "+znaku_txt+"!"); 
    textpole.value = textpole.value.substr(0,199);
  }
}

function show_enlarged(){
  document.getElementById('rozsirene').style.display = '';
  document.getElementById('zobrazit').style.display = 'none';
  document.getElementById('skryt').style.display = '';
  document.getElementById('rozs').value = 1;
  document.cookie = 'rozs=1';
}

function hide_enlarged(){
  document.getElementById('rozsirene').style.display = 'none';
  document.getElementById('zobrazit').style.display = '';
  document.getElementById('skryt').style.display = 'none';
  document.getElementById('rozs').value = 0;
  document.cookie = 'rozs=0';
}

function aktivace(id,txt){
  code = prompt(txt,'');
  if (code){
    document.getElementById(id).value = code;
    return true;
  }else{
    return false;
  }
}

function enable_time(day_check,check){
  if (check){
    document.getElementById(day_check+'_od').disabled = false;
    document.getElementById(day_check+'_do').disabled = false;
  }else{
    document.getElementById(day_check+'_od').disabled = true;
    document.getElementById(day_check+'_do').disabled = true;
  }
}