Apachesolr is installed as a mutli installation on the Drupal 6 platform.

The folllowing functions works

function tb_misc_apachesolr_modify_query(&$query, &$params, $caller) {
  $query->add_filter('hash', apachesolr_site_hash());
}

function tb_misc_apachesolr_delete_index_alter(&$query) {
  //$query = 'hash:' . apachesolr_site_hash();
}

However I need to add 2 custom fields to include into the search results. I tried the following.

// filters search results by site
function tb_misc_apachesolr_modify_query(&$query, &$params, $caller) {
  $query->add_filter('hash', apachesolr_site_hash());
  $params['fl'] .= ',sm_field_author_first_name,sm_field_images,sm_field_author_last_name';
}

function tb_misc_apachesolr_update_index(&$document, $node) {
  if ($node->type == 'author') {
    $document->addField('sm_field_author_first_name', $node->field_author_first_name);
    $document->addField('sm_field_author_last_name', $node->field_author_last_name);
  }
}

function tb_misc_apachesolr_delete_index_alter(&$query) {
  //$query = 'hash:' . apachesolr_site_hash();
}

I deleted the search index and manually run cron. At this point Apachesolr was throwing out errors.

Any help will be grately appreciated.

Sammyb