[%########################################
  form_select_option( item, label_field, value_field, picked )
     Display a single OPTION item for use in a <SELECT> dropdown.
  ########################################-%]
[%- UNLESS plain -%]
  [%- SET use_label_field = label_field || value_field;
      SET value           = item.$value_field;
      SET label           = item.$use_label_field; -%]
[%- END -%]
[%- SET is_picked = ( value == picked ) ? ' SELECTED' : '' -%] 
<option value="[% value %]"[% is_picked %]>[% label %]</option>
