Reverse comments in page template?

I would like to make a sort of guestbook and have used a page to do this, the only problem being I would like the comments that are written to be in descending order so the comment on the top of the page is the last one that was left. I would also like to put the comment box on top of the comments so that it is always at the top. I need this for this my one page only. Can anyone help me?? Thanks in advance!