Comments section

Hi Sakin, at the bottom of the page in the comments section, I'd like to add two more things that I've seen on other websites: 1. A field that asks the person who comments for an optional website address (great for bloggers) 2. A tickbox where the person who comments can decide to be notified by email when I or somebody else replies to this post (like at the bottom of this page) How can I do this? Thanks a lot!