title: JS floating message box with fade
body: <p>(I'm not sure what is it call!)
  For example you enter a website, you see a the left there is a button with an arrow ( &lt;- ), sroll with you, and when you click in a box expand, when you click agian the box close.</p>
  
  <p>PLeas tell me what is it and where I can find some demo code :D
  Thanks</p>