// hide default prefix (INBOX., mail/ or other)
$quoted_prefix=preg_quote($default_folder_prefix,'/');
$prefix_length=(preg_match("/^$quoted_prefix/",$old) ? strlen($default_folder_prefix) : 0);
// hide default prefix (INBOX., mail/ or other)
$quoted_prefix=preg_quote($default_folder_prefix,'/');
$prefix_length=(preg_match("/^$quoted_prefix/",$old) ? strlen($default_folder_prefix) : 0);