function strToUtf8($vector) {
  $from_chr = mb_detect_encoding ( $vector, array (
      'UTF-8',
      'ASCII',
      'EUC-CN',
      'CP936',
      'BIG-5',
      'GB2312',
      'GBK' 
  ) );
  if ($from_chr != "UTF-8") {
    $vector = mb_convert_encoding ( $vector, 'UTF-8', array (
        'UTF-8',
        'ASCII',
        'EUC-CN',
        'CP936',
        'BIG-5',
        'GB2312',
        'GBK' 
    ) );
  }
  return $vector;
}