scrollTo with easing and a callback function

Question

Here is my code thus far:

    $('.my_button').click(function() {

        $.scrollTo( '#my_anchor', 1200, {easing:'easeInOutExpo'}, function() {          

            // function not working here

        });

    });

The callback function worked previously, but since I changed to the scrollTo method with easing, it doesn't any more!

Just to make it clear I only need to know how to get my callback function working again, everything else is fine.

Solution

There is no forth parameter, but the third parameter (settings) accepts an onAfter callback

$.scrollTo( '#my_anchor', 1200, {easing:'easeInOutExpo', onAfter: function() { }});

from the source code on settings:

 * @param {Object,Function} settings Optional set of settings or the onAfter callback.
 *   @option {String} axis Which axis must be scrolled, use 'x', 'y', 'xy' or 'yx'.
 *   @option {Number} duration The OVERALL length of the animation.
 *   @option {String} easing The easing method for the animation.
 *   @option {Boolean} margin If true, the margin of the target element will be deducted from the final position.
 *   @option {Object, Number} offset Add/deduct from the end position. One number for both axes or { top:x, left:y }.
 *   @option {Object, Number} over Add/deduct the height/width multiplied by 'over', can be { top:x, left:y } when using both axes.
 *   @option {Boolean} queue If true, and both axis are given, the 2nd axis will only be animated after the first one ends.
 *   @option {Function} onAfter Function to be called after the scrolling ends.
 *   @option {Function} onAfterFirst If queuing is activated, this function will be called after the first scrolling ends.