Where should the rjs file be inserted in case of updating a child object


I have a BlogPost objects' 'show' page where I insert new comments. Both
BlogPost and comment have two separate resources. This in my 'route.rb'
file looks like this

   map.resources blog_posts, :has_many => :comments

So, 'comments' is a child of 'blog_posts'. So, in BlogPost 'show' page
I'm using form_remote_tag to input text for new comments. The current
scenario is, the new comments gets inserted into the database without
any problem but how do I update the 'show' page to show the new comment
that was just inserted using ajax? I mean should I create a .rjs as
'create.rjs' in 'comments' view folder or should it be as 'show.rjs' in
'blog_posts' view folder?