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(){
  $("button").click(function(){
    var txt="";
    txt+="Document width/height: " + $(document).width();
    txt+="x" + $(document).height() + "\n";
    txt+="Window width/height: " + $(window).width();
    txt+="x" + $(window).height();
    alert(txt);
  });
});
</script>
</head>
<body>

<button>Display dimensions of document and window</button>

</body>
</html>

Result:

W3Schools.com - Try it yourself

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