Deleting directory

[cekirge]

Users upload files to a directory that is created when they start uploading, after like 10 days i want to delete the directory, but whenever i try to delete it i get an permission denied error for the files, thus making me impossible to delete the directory.
I also tried
exec ("rm -rf /path/to/directory");
that did not work either,
What could be my problem?

[matt_4013]

Check your file permissions, and make sure the sticky bit is not set. This would allow users to upload to the directory, and create them, but not delete them.