title: Keycode for Print Screen (44 is not working)
body: <p>So I want to test if visitors of my site have pressed Print Screen button.</p>
  
  <p>As much as I was looking for, there were no information to be found how to do it. All I found was, that ir is supposed to be keyCode == 44.</p>
  
  <p>With all the other buttons I tried there was no problem.</p>
  
  <p>Where is my mistake?</p>
  
  <p>Here's similar, working code for enter button:</p>
  
  <pre><code>window.addEventListener("keydown", checkKeyPressed, false);
  
  function checkKeyPressed(e) {
      if (e.keyCode == "13") {
          alert("The 'enter' key is pressed.");
      }
  }
  </code></pre>