title: How to automatically disable and enable scroll for pre tag
body: <p>I need to implement down and up scroll when height of pre will be became more than X px. My friend behind cell phone says you can, and you need define maximum px of pre tag and when pre overflow, it must be visible, but I don't know css well and I couldn't implement this.</p>
  
  <p>UPDATE:</p>
  
  <p>Indeed U need to if my lines bigger than X line scroll enable and else it's invisible.</p>
  
  <p>Can you put this code?</p>