def comment
    Post.find(params[:id]).comments.create(params[:comment])
    flash[:notice] = "Added Your Comment" 
    redirect_to :action => "show", :id => params[:id]
  end



<% for comment in @post.comments %>
        <%= comment.body %>
        <hr />
<% end %>
<% form_tag :action => "comment", :id => @post %>
        <%= text_area "comment", "body" %><br />
        <%= submit_tag "Comment!" %>