FB Page Tab anchor click smooth scroll

fb-canvas-click-scroll.js

function scrollFBTo(y){
  FB.Canvas.getPageInfo(function(pageInfo) {
    $({y: pageInfo.scrollTop}).animate({
      y: y
    }, {
      duration: 500,
      step: function(offset) {
        FB.Canvas.scrollTo(0, offset);
      }
    });
  });
}