Problem with adding entries to a guest book using ajax

Hi!

I’ve got the following problem:

When user successfully adds new entry to the guest book i’d like to
highlight it (so i need to update a div and run highlight effect on it)
and i’d like also to swap entry form with some info (another update).

When the validation fails i’d like to display errors above the form
(only one update,but different then the others).

How to do it? Doing one of these things at a time is simple, but i don’t
know how to combine them.

Thanks in advance