Wordpress automatic update / permission issue

Hi there, I installed WP on Ubuntu and I’m having issues updating WP automatically, it’s asking for FTP detail. Also when I add the following to wp-config.php for automatic update I get a failed issue.

define(‘FS_METHOD’,‘direct’);

Can anyone tell me how to fix this issue or how to set the permission on the server so WP has permission to make changes. At the moment I’m suing SSH/SFTP to connect to the server for file modification but after modifying it won’t allow me to save any of the edited files.

Thanks, Zak