title: Rails form_for with collection_select
body: <p>I'm trying to create a field that creates an instance of the Ranking class. It has a comment field already which sets the <code>params[:ranking][:comment]</code> but now I want to add a drop down that displays something like:</p>
  
  <p>1: horrible, 2: poor, 3: mediocre, 4: good, 5: great</p>
  
  <p>I would like these to set the params[:ranking][:score] to a value 1-5 so that in my create method I can do something like this:</p>
  
  <pre><code> @ranking = Ranking.new( #....
                          :score =&gt; params[:ranking][:score])
  </code></pre>
  
  <p>My form looks like this right now:</p>
  
  <pre><code>&lt;%= form_for([@essay, @ranking]) do |f| %&gt;
    &lt;%= render 'shared/error_messages', :object =&gt; f.object %&gt;
    &lt;div classs="field"&gt;
      &lt;%= f.text_area :comment %&gt;
    &lt;/div&gt;
    &lt;div classs="field"&gt;
        &lt;%= #something here!%&gt;
    &lt;/div&gt;
    &lt;div class="actions"&gt;
      &lt;%= f.submit "Submit" %&gt;
    &lt;/div&gt;
  &lt;% end %&gt;
  </code></pre>
  
  <p>I know that I need to use the <code>collection_select</code> but I haven't been able to get it working. </p>