title: Increase div width size when collape sidebar
body: <pre><code>&lt;style type="text/css"&gt;
    .collapse {
    height: auto;
    width: auto;
  }
  
  .collapse.in.width {
    width: auto;
  }
  &lt;/style&gt;
  </code></pre>
  
  <p>My horizontal collapse works fine however once collapsed I want the div class=span4 width to increase to the available viewport width space e.g: 8. and the button label to change to 'Show' and vice-versa using JQuery.</p>