title: Within a category, "Seach all posts" checkbox, how to?
body: <p>I have set up my routes so I can search all posts with:</p>
  
  <pre><code>/posts/search/foobar
  </code></pre>
  
  <p>or search inside a category</p>
  
  <pre><code>/posts/category/1/search/foobar 
  </code></pre>
  
  <p>It works pretty well, when someone is browsing an specific category it does search just posts that belongs to that category.</p>
  
  <p>When inside a category, I want to place a checkbox to "Search all the posts"</p>
  
  <p>My search form:</p>
  
  <pre><code>&lt;% form_for :posts, :url =&gt; {:controller =&gt; :posts, :action =&gt; :index} do |f| %&gt;
    Search: &lt;%= f.text_field :search %&gt;
    &lt;% if params[:cat] %&gt;
      &lt;%= f.check_box :ignore_cat, '1', false %&gt; Search all the posts?
    &lt;% end %&gt;
    &lt;%= f.submit 'Go' %&gt;
  &lt;% end %&gt;
  </code></pre>
  
  <p>How can I force to change the route?</p>