function insertTypes(marka_id, typ_sel)
{
  var tsel = document.getElementById('t');

  while (tsel.childNodes.length)
    tsel.removeChild(tsel.firstChild);

  var typ_id = 0;

  var opt = document.createElement('OPTION');
  var txt = document.createTextNode('Wszystkie modele'
    + (marka_id != 0 ? ' ' + marki[marka_id] : ''));
  opt.value = 0;
  opt.appendChild(txt);
  tsel.appendChild(opt);

  if (marka_id != 0)
    for (typ_id in typy[marka_id]) {
      opt = document.createElement('OPTION');
      txt = document.createTextNode(marki[marka_id] + ' ' +
        typy[marka_id][typ_id]);
    
      opt.value = typ_id;
      if (typ_id == typ_sel) opt.selected = "selected";
      opt.appendChild(txt);
      tsel.appendChild(opt);
    }
  else
    for (typ_id in typyw) {
      opt = document.createElement('OPTION');
      txt = document.createTextNode(typyw[typ_id]);
    
      opt.value = typ_id;
      if (typ_id == typ_sel) opt.selected = "selected";
      opt.appendChild(txt);
      tsel.appendChild(opt);
    }
}