<!-- the html code -->

​

<button id="topBtn" title="Go to top">Top</button>

​

<style>

body{

  height:3000px;

}

​

button{

  position:fixed;

  bottom:30px;

  right:30px;

}  

</style>

​

<script>

$(document).ready(function(){

  // When the user scrolls down 20px from the top of the document, show the button

  $(window).scroll(function(){

    scrollFunction();

  });

​

  function scrollFunction() {

    if ($(this).scrollTop() > 20) {

      $('#topBtn').fadeIn();

    } else {

      $('#topBtn').fadeOut();

    }

  }

​

  // When the user clicks on the button, scroll to the top of the document

  $('#topBtn').click(function(){

    $('html, body').animate({scrollTop: 0}, 800);

    return false;

  });

});

​

​

</script>