public static function assoc_to_keyval($assoc = null, $key_field = null, $val_field = null)
{
if (empty($assoc) or empty($key_field) or empty($val_field)) {
return null;
}
$output = array();
foreach ($assoc as $row) {
if (isset($row[$key_field]) and isset($row[$val_field])) {
$output[$row[$key_field]] = $row[$val_field];
}
}
return $output;
}