An error of the guest book in week 7 practical exercises

Today, I tried to add the guest book which is in the week 7 practical exercises to my project. However, I found a problem that when I wanted to change the page of the guest book to see other messages, it did not work.

I read through the php script and found the bug which is the php program has not the syntax to get the value of the attribute "offset" passed by the URL.

If you add the following syntax into your php script, the problem will solve and then you can see the messages on different pages.