Need to add css class on sub comments

hi, I need to add css class on sub comments. I am using (single)same partial view for showing the comments. comment 1 comment 1.1 comment 1.2 comment 1.3 comment 2 comment 3 comment 4 comment4.1 Html.renderpartialview("democommentviewmodel", comments); I am using this in html page. once I put reply comment. I need to show the left side border for showing group of sub comments in the comment.