Untitled

<html>
<head>
<!--Put the following CSS Code into the CSS Code box to tidy it up a bit.-->
/* START */
#myBtn {
  display: none;
  position: fixed;
  bottom: 25px;
  right: 25px;
  z-index: 99;
  border: none;
  outline: none;
  background-color: green;
  color: white;
  cursor: pointer;
  padding: 20px;
  border-radius: 13px;
}

#myBtn:hover {
  background-color: #555;
}
/* END */
</head>
<body>

<button onclick="topFunction()" id="myBtn" title="Go to top">Top</button>


 <!--You have to leave the JS in the script tag because there is an issue with it for some reason, I have tested.-->
<script>
// When the user scrolls down 20px from the top of the document, show the button
window.onscroll = function() {scrollFunction()};

function scrollFunction() {
    if (document.body.scrollTop > 20 || document.documentElement.scrollTop > 20) {
        document.getElementById("myBtn").style.display = "block";
    } else {
        document.getElementById("myBtn").style.display = "none";
    }
}

// When the user clicks on the button, scroll to the top of the document
function topFunction() {
    document.body.scrollTop = 0;
    document.documentElement.scrollTop = 0;
}
</script>

</body>
</html>