WindowsBy default, write permission is not granted on your directory. Please open a ticket and specify your account name, domain and full path to the directory that you need write permission on.
If your account is on Unix, and you are using PHP you need to change the directory mode to 777 if you wish to add or remove files in the directory. To be able to write to files, you need to chmod the files to 666.
For Perl scripts running on Unix, the normal permission should apply, i.e. 755 for directories and 644 for files. The Perl script runs under your user privileges it can write to your files just as you could through FTP.