title: How to upgrade the :update=>'div_id' option of remote_form_for from Rails 2 to Rails 3?
body: <p>I can't figure out how to upgrade this code from Rails 2 to Rails 3:</p>
  
  <pre><code>&lt;% remote_form_for(item, :update =&gt; 'div_id') do |f| %&gt;
  ... 
  </code></pre>
  
  <p>I tried this:</p>
  
  <pre><code>&lt;%= form_for :item, :remote =&gt; true, :url =&gt; { :controller =&gt; "items", :action =&gt; "create" }, :update =&gt; 'div_id' do |f| %&gt;
  ...
  </code></pre>
  
  <p>It creates the new item but <strong>it fails in updating the content</strong> within <code>&lt;div id="div_id"&gt;&lt;/div&gt;</code> tags. It seems Rails 3 no longer supports the "<code>:update</code>" option for a remote <code>form_for</code>. Any suggestion?</p>