function setSubSelectOptions(director_select_id, sub_select_id, sub_options)
{
  var director = $('#' + director_select_id);
  var sub_select = $('#' + sub_select_id);
  director_val = director.val();            // 1
  sub_select.html('');                      // 2

  if(sub_options[director_val])
  {
    for(var i = 0; i < sub_options[director_val].length; i++)
    {
      $('#' + sub_select_id).append('<option value="' + sub_options[director_val][i] + '">' + sub_options[director_val][i] + '</option>');
    }
  }
}