fb_scrolling.html

<!-- anchor example -->
<a href="#" onclick="FB.Canvas.scrollTo( 0, 500 );">Click here to enter</a>

<!-- anchor with jQuery dynamic placement example -->
<a href="#" onclick="FB.Canvas.scrollTo( 0, $('.enter-btn').offset().top );">Click here to enter</a>

<!-- page load example -->
<script type="text/javascript">
  window.fbAsyncInit = function() {
    FB.init({
      appId      : 'xxx', // App ID
      channelUrl : 'channel.html', // Channel File
      status     : true, // check login status
      cookie     : true, // enable cookies to allow the server to access the session
      xfbml      : true  // parse XFBML
    });

    FB.Canvas.scrollTo(0, 0);
  };
</script>