title: Rails remote forms validation
body: <p>Just a simple question, I have followed the <a href="http://railscasts.com/episodes/136-jquery-ajax-revised" rel="nofollow">railscast</a></p>
  
  <p>It's nice how for remote true works, but how can I validate the model ? </p>
  
  <p>I have this one</p>
  
  <pre><code>&lt;%= form_for [:admin,@course], remote: true  do |f| %&gt;
    &lt;div class="field"&gt;
      &lt;%= f.label :title, "The title:" %&gt;&lt;br /&gt;
      &lt;%= f.text_field :title %&gt;
    &lt;/div&gt;
    &lt;div class="field"&gt;
      &lt;%= f.label :description, "Descripcion:" %&gt;&lt;br /&gt;
      &lt;%= f.text_area :description %&gt;
   &lt;/div&gt;
   &lt;div class="actions"&gt;
     &lt;%= f.submit "Send"%&gt;
   &lt;/div&gt;
  &lt;% end %&gt;
  </code></pre>
  
  <p>How I handle the error?</p>
  
  <pre><code>def create
  
    @course = Course.new(params[:course])
  
    respond_to do |format|
      if @course.save
        format.html { redirect_to admin_index_url, :notice=&gt; 'Done !!' }
        format.js
      else
        format.html { flash.now[:alert] = "Not done" 
                      render "new"
                    }
        format.js
      end
    end        
  end
  </code></pre>
  
  <p>Any ideas why this does not work?</p>