title: bootstrap 3 column layout, main content before two sidebar
body: <p>Using Bootstrap, for the both left and right sidebar 3 column layout, we don't know how to edit the css to put the main content above both sidebars, please advise how to do, thanks.</p>
  
  <p>We tried following code, but Not working:</p>
  
  <pre><code>&lt;div class="row"&gt;
    &lt;div class="span6"&gt;
      main content
    &lt;/div&gt;
    &lt;div class="span3 pull-left"&gt;
      left bar
    &lt;/div&gt;
    &lt;div class="span3 pull-right"&gt;
      right bar
    &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>please advise how to do it, thanks.</p>