Guestbook v1.5

If anyone could get me a helping hand here, I would appreciate it greatly indeed. I have the problem (and found no description):

# base directory to all guestbook files from the server root without trailing "/"
$base_dir = "/home/usr/you/book";

I have no idea what's the correct path above.....

I set up the book under the url

www.austria-philippines.at/book/guestbook.html

www.arj.at/book/guestbook.html

Regards, Arthur

By the way, mind telling me what's better, v1.5 or the advanced version of the guestbook?