Tryit Editor v1.8

Source Code:

<!DOCTYPE html>
<html>
<head>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js">
</script>
<script>
$(document).ready(function(){
  $(".btn1").click(function(){
    $("p").fadeOut(1000,function(){
      alert("fadeOut() method is finished!");
    });
  });
  $(".btn2").click(function(){
    $("p").fadeIn(1000,function(){
      alert("fadeIn() method is finished!");
    });
  });
});
</script>
</head>
<body>

<p>This is a paragraph.</p>
<button class="btn1">Fade out</button>
<button class="btn2">Fade in</button>

</body>
</html>

Result:

W3Schools.com - Try it yourself

Edit the code above and click "Submit Code" to see the result.