I think I resolve it.
Since I just start to learn programing specially perl, the code looks not fancy. Please check it out and give me a guide.

I added:
foreach $field (@fields) {
$kategory{$field} = &kategorie_title_mb($field);
}


And changed:
it was...
$values{$field} ?
($output .= "<OPTION SELECTED>$field\n") :
($output .= "<OPTION>$field");

now...
$values{$field} ?
($output .= "<OPTION SELECTED VALUE=\"$field\">$kategory{$field}\n") :
($output .= "<OPTION VALUE=\"$field\">$kategory{$field}");

I saw the silimar question on forum. please give me and them help.
Thanks.