function focusInput (id)
{
  var e;

  if (document.getElementById)
  {
    e = document.getElementById (id);
  }
  else if (document.all)
  {
    e = document.all[id];
  }
  else if (document.layers)
  {
    e = document.layers[id];
  }
  
  e.focus();
}

function AddToFavorite ()
{
  if(document.all)
  {
    window.external.AddFavorite (location.href,document.title);
  }
  else if (window.sidebar)
  {
    window.sidebar.addPanel (document.title, location.href,'');
  }
  else
  {
     alert ('Bohužel, stránku musíte do oblíbených přidat ručně, např. stiskem <Ctrl-D>.');
  }
}

function ChangePreview (div_id, a_id, img_id, large_url, full_url, loading)
{
  var div, a, img;

  if (document.getElementById)
  {
    div = document.getElementById (div_id);
    a = document.getElementById (a_id);
    img = document.getElementById (img_id);
  }
  else if (document.all)
  {
    div = document.all[div_id];
    a = document.all[a_id];
    img = document.all[img_id];
  }
  else if (document.layers)
  {
    div = document.layers[div_id];
    a = document.layers[a_id];
    img = document.layers[img_id];
  }

  a.href = full_url;
  img.src = loading;
  div.style.display = 'block';
  img.src = large_url;

  return false;
}

function CountLeft (text_id, counter_id, limit)
{
  var text, counter;

  if (document.getElementById)
  {
    text = document.getElementById (text_id);
    counter = document.getElementById (counter_id);
  }
  else if (document.all)
  {
    text = document.all[text_id];
    counter = document.all[counter_id];
  }
  else if (document.layers)
  {
    text = document.layers[text_id];
    counter = document.layers[counter_id];
  }
  
  left = limit - text.value.length;

  if (left < 0)
  {
    text.value = text.value.substring (0, limit);
    left = limit - text.value.length;

    alert ('Byla překročena maximální dovolená délka textu.');
  }
  
  counter.innerHTML = 'Zbývá znaků: <span class="bold">' + left + '</span>';
}