<% Story.commentform %>
macro checks if user is logged in and not blocked if true, render form to add a comment

Sourcecode in Story/macros.js:
1:   function commentform_macro(param) {
2:      if (session.user) {
3:         res.data.action = this.href("comment");
4:         (new Comment()).renderSkin("edit");
5:      } else {
6:         Html.link({href: this.site.members.href("login")},
7:                   param.text ? param.text : getMessage("Comment.loginToAdd"));
8:      }
9:      return;
10:  }