scroll-to.js

// http://lions-mark.com/jquery/scrollTo/
// $('body').scrollTo('#target');
// $('#content').scrollTo(500);
// $('body').scrollTo('#post-5', { duration:'slow', offsetTop : '50' });
// $('body').scrollTo('#target', {}, complete_callback);

$.fn.scrollTo = function( target, options, callback ) {
  if(typeof options == 'function' && arguments.length == 2){ callback = options; options = target; }
  var settings = $.extend({
    scrollTarget  : target,
    offsetTop     : 50,
    duration      : 500,
    easing        : 'swing'
  }, options);
  return this.each(function(){
    var scrollPane = $(this);
    var scrollTarget = (typeof settings.scrollTarget == "number") ? settings.scrollTarget : $(settings.scrollTarget);
    var scrollY = (typeof scrollTarget == "number") ? scrollTarget : scrollTarget.offset().top + scrollPane.scrollTop() - parseInt(settings.offsetTop);
    scrollPane.animate({scrollTop : scrollY }, parseInt(settings.duration), settings.easing, function(){
      if (typeof callback == 'function') { callback.call(this); }
    });
  });
}