title: Rails text_field with no method associated
body: <p>i'm having a problem to create a text_field without a method association. Maybe i even don't need it :-)</p>
  
  <p>I have two radio_buttons associated to the same method:</p>
  
  <pre><code>&lt;%= radio_button :comment, :author, "anonymous" %&gt; Anonymous &lt;br&gt;
  &lt;%= radio_button :comment, :author, "real_name" %&gt; Name &lt;br&gt;
  </code></pre>
  
  <p>What i would like to do is to have an text_field which when the user click on the radio_button "real_name" i can verify the value in this new text_field. </p>
  
  <p>Basically my Controller would be something like:</p>
  
  <p>@comment = Comment.new(params[:comment])</p>
  
  <p>if @comment.author == "real_name"
   @comment.author = "value-from-the-new-textfield
  end</p>
  
  <p>There is any way to do it?</p>
  
  <p>Regards,</p>
  
  <p>Victor</p>