title: How to make a DIV scrollable instead of BODY?
body: <p>I want my page's BODY <strong><em>not to be</em></strong> scrollable but a DIV inside the BODY should be scrollable.
  I have this in my css file:</p>
  
  <hr>
  
  <pre><code>body {
  overflow:hidden
  }
  
  .mainSection {
  overflow:scroll
  }
  </code></pre>
  
  <hr>
  
  <p>but it doesn't work and the DIV doesn't become scrollabel (it just shows two disabled scroll bars for the DIV)!</p>