new FTP function

Hi II would like to see "ftp_dir_exists()" function in PHP, right now its kinda unreasonable to expect people to use hacks such as "is_dir()" and having to re-authenticate just to check if the dir exists, I also dont think its good idea to use "ftp_chdir()" just to check if the directory exists, because its shows errors if the directory doesn't exists. i think there should be a way to check if the directory exists without having to resort to hackish ways, or having to authenticate again.