title: Enable two scroll bars with bootstrap
body: <p>I just started to learn CSS and I want a page with two independent columns, each has a scroll bar. And my CSS is like (span4 and span8 are div class)</p>
  
  <pre><code>body { 
         height: 100%; 
         overflow: hidden; } 
  .span4 {
          height: 100%;
          overflow: auto; }
  .span8 { 
          height: 100%;
          overflow: auto; }
  </code></pre>
  
  <p>It seems not working. I have to specify the height of span4 and span8, like "400px", but I don't want to do this (not responsible?, also I don't know the height). Do I miss something? If this can be done without JavaScript, that'll be good (I know little of js). Thanks.</p>
  
  <p>Update: still can't figure it out. Here is a link to illustrate: <a href="http://jsfiddle.net/hPfKk/2/" rel="nofollow">http://jsfiddle.net/hPfKk/2/</a></p>