Advanced guestbook - do I have to open it in a new page?

Hello, I have web pages. If I run advanced book in a "_blank page", that's ok. But the problem is, if I run it in my pages. Links and variables are bad... I don't know how to make the menu as you have. I think this> you have link "Guestbook" (http://proxy2.de/guestbook/) and guestbook opens at the right side i your pages. I have in my pages link "./index.php?file=guestbook"... How to make link to open guestbook at the right side in the directory "guestbook" and not over the file=.... . Because then you pages go well and my go bad...

Thanks a lot,

BTW: I have new language script for your advance book - czech language

Tom