uploading a picture


when i try to upload a message i get this message...

The file did not upload. Filename: 'PICS 003.jpg'
Error: Either destination folder does not exist or is not writable. (chmod 777) [e107_files/public/avatars/]

what does that mean
how do i fix it...

thank you
Can I say since the server is Linux (3 guesses how I figured that out), don't have spaces in the names of the files that are being uploaded as windows is stupid when it comes to spaces and Linux is very pedantic.