gistfile1.txt

<!-- file is: show.html.erb of the POST controller ...not Comment controller -->

<% form_for @post do |f| %>
  <!-- code to show my post -->
  <!-- there is more here to show my post -->
  
  f.text_field :body
 

  <% form_for [@post, Comment.new] do |f| %>
    Body: <%= f.text_field :body %>
    <p><%= f.submit "Add Comment" %></p>
  <% end %>
<% end %>