case "xls":
    // begin file
    $xlsstring = pack( "ssssss", 0x809, 0x08, 0x00,0x10, 0x0, 0x0 );
    // write 1. line = field names
    for ($i=0; $i < count($f_lang);$i++) {
      $xlsstring .= pack( "s*", 0x0204, 8+strlen($f_lang[$i]), 0, $i, 0x00, strlen($f_lang[$i]) );
      $xlsstring .= $f_lang[$i];
    }
    // write content
    $a=0;
    foreach ($export_array as $line) {
      for ($i=0;$i < count($line); $i++) {
        // special patch for xl since it doesn't understand \r as the line ende
        $line[$i] = str_replace("\r", "", $line[$i]);
        $xlsstring .= pack( "s*", 0x0204, 8+strlen($line[$i]), $a+1, $i, 0x00, strlen($line[$i]) );
        $xlsstring .= $line[$i];
      }
      $a++;
    }
    $xlsstring .= pack("ss", 0x0A, 0x00);
    echo $xlsstring;
    break;

function make_export_array($query) {
  $result = db_query($query) or db_die();
  while ($row = db_fetch_row($result)) {
    $line = array();
    foreach($row as $element) { $line[] = $element; }
    $export_array[] = $line;
  }
  return $export_array;
}