def downvote
      security_transgression_unless @comment.can_be_voted_on_by?(@user) &&\
        @comment.thread.config.comment_voting.to_sym == :ld

      @comment.downvote_from @user

      respond_to do |format|
        format.html { redirect_to @thread }
        format.js { render :vote }
      end
    end
def downvote
      security_transgression_unless @comment.can_be_voted_on_by?(@user) &&\
        @comment.thread.config.comment_voting.to_sym == :ld

      @comment.downvote_from @user

      respond_to do |format|
        format.html { redirect_to @thread }
        format.js { render :vote }
      end
    end
PUT /comments/1/downvote