Member variable in controller

I have a news_controller. The ‘show’ action shows an article, and at
the bottom of the page there is a form to submit a new comment. The
show method sets @article member variable to the article about to be

def show
@article = Article.find(params[:id])

When the addcomment action is called, when the submit clicked. I need
to know the id of the article in the addcomment method.

def comment
comment =
comment.article = @article #this does not work
comment.text = params[:comment][:text]
comment.created =
flash[:notice] = ‘Comment was successfully added.’
redirect_to :action => ‘show’

My form looks like this:
<% form_tag :action => ‘comment’ do %>
<%= render :partial => ‘commentform’ %>
<%= submit_tag “Submit” %>
<% end %>

and _commentform.rhtml is
<%= error_messages_for ‘comment’ %>

<%= text_area 'comment', 'text' %>

I think my question is very simple, hopefully I articulated it well
enough… Am I attacking this from the wrong direction?