Need help urgently please?

Guestbook 1.5

Ive deleted a few posts made by some idiot on my guestbook using the Admin login page but now my guestbook is missing some ID numbers which looks really bad. It doesnt seem to want to reallocate the numbers evenly so im missing some.

How do i reset the ID's so they count up like 1,2,3,4,5,6,7,8,9,10 and not
1,2,4,7,8,9,10 ?

I even changed the guest_id.txt to match the number of posts on the guestbook but it doesnt seem to make a difference to the HTML page?

Any help appreciated
Thank U.