function pk_nav_select_on_change(id) 
{
  var e = document.getElementById(id);
  var index = e.selectedIndex; 
  if (e.value.substr(0, 4) != 'none')
  { 
    document.location = e.options[index].value;
  }
  else 
  { 
    var i;
    var winner = 0;
    for (i = 0; (i < e.options.length); i++)
    {
      if (e.options[i].defaultSelected)
      {
        winner = i;
        break;
      }
    }
    e.selectedIndex = winner;
  }
}