i know, http://hnshowcase.com 's provides more info than what i have done.
but, i wanted to build it anyway as i have been a thinker and not a doer for a long time. :)
You don't need to preface your comment with the name of the user you are responding to. The fact that your comment is right below and indented one level is a dead giveaway that you are responding to the parent comment.