This plugin provide Ajax enabled comments system with paging,posting and form validation to your WordPress blog.
Ajax page navigation.
Pagination can cause a duplicate content issue with search engines.YAAPC can automatically generate “noindex,follow” meta tag in your paged comments page to avoid duplicate content in search engines that may hurt your rankings.
Ajax comment posting.
Posting comments via Ajax,without page refreshing.
Comment form validation.
validate the user input in comment form before sending to server.