title: How to make a "pop-up"-info box and a transparent gray over page?
body: <p>I am making a page and I want to achieve something similar to this when clicking a button:</p>
  
  <p>from this:
  <a href="http://i.imgur.com/3zlPn2w.jpg" rel="nofollow">http://i.imgur.com/3zlPn2w.jpg</a> </p>
  
  <p>to this:</p>
  
  <p><a href="http://i.imgur.com/nVqe9bv.jpg" rel="nofollow">http://i.imgur.com/nVqe9bv.jpg</a></p>
  
  <p>Like a transparent gray coming up over teh page with a information box. How is that done?
  Thanks in advance!</p>