title: Rails: redirect_to with :error, but flash[:error] empty
body: <p>I'm trying to do a redirect while setting the flash[:error] value. (Rails 3.0.10)</p>
  
  <p>In my view I have</p>
  
  <pre><code>&lt;p id="error"&gt;&lt;%= flash[:error] %&gt;&lt;/p&gt;
  &lt;p id="notice"&gt;&lt;%= flash[:notice] %&gt;&lt;/p&gt;
  </code></pre>
  
  <p>If I do a <code>redirect_to show_path, :notice =&gt; "ok"</code> it works fine, but if I do <code>redirect_to show_path, :error =&gt; "error"</code> it doesn't show up.</p>
  
  <p>what could I be missing?</p>