4.7 port: convert db script form according to the new forms api

I have tryed to update the database script form according to the new forms api: the page shows, but the sql results aren't shown, some more testing needed:

function dba_script($edit = array()) {
  $output = '';
  if (!empty($edit['dba_script'])) {
    unset ($output);
    // execute each sql statement individually
    foreach (explode(';', $edit['dba_script']) as $sql) {
      if (trim($sql) == '')
        break;
      $result = dba_execute_script($sql);
      if ($result && $result != 1 && db_num_rows($result)) {
        while ($row = db_fetch_array($result)) {
          if (!$header) {
            $header = array_keys($row);
          }
          $rows[] = array_values($row);
        }
      }
      if (!is_null($rows)) {
        $output .= 'Result:'.theme('table', $header, $rows);
        //$output .= form_group(t('Result'), $group);
	//$form[$sql] = array(
	//    '#type' => 'fieldset',
	//    '#title' => $sql,
	//    '#collapsible' => FALSE,
	//    '#collapsed' => FALSE,
	//    '#description' => $group
	//    );
      }
      unset ($rows);
    }
  }

  if (user_access('dba administer database')) {
    //$group = form_textarea(t('Database script'), 'dba_script', $edit['dba_script'], 70, 10, t('Enter the text of your database script.  This will be executed directly in your database, so the action can not be undone.  Be sure to wrap the table name in {}.  For example, if counting the rows in the \'accesslog\' table, you would enter the following simple script: \'SELECT COUNT(*) FROM {accesslog}\'.'));
    //$group .= form_submit(t('Execute script'));
    //$group .= l(t('Cancel'), 'admin/database');
    //$output .= form_group(t('Script'), $group);
	$form['script'] = array(
	    '#type' => 'fieldset',
	    '#title' => t('Script'),
	    '#collapsible' => FALSE,
	    '#collapsed' => FALSE
	    );
	$form['script']['dba_script'] = array(
	    '#type' => 'textarea',
	    '#title' => t('Database Script'),
	    '#description' => t('Enter the text of your database script.  This will be executed directly in your database, so the action can not be undone.  Be sure to wrap the table name in {}.  For example, if counting the rows in the \'accesslog\' table, you would enter the following simple script: \'SELECT COUNT(*) FROM {accesslog}\'.'),
	    '#default_value' => '',
	    '#cols' => 70,
	    '#rows' => 10
	    );
	$form['script']['Execute script'] = array(
	    '#type' => 'submit',
	    '#value' => 'Execute script'
	    );
    
  }

  $output .= drupal_get_form( 'admin/database/script', $form);
  return $output;
}