animateVerticalScroll.js

function animateVerticalScroll(px, scope, callback, options) {
  var time,
    callbackCalled = false,
    obj;

  options = options || {};
  options.time = options.time || 1000;

  currScroll = scope.scrollTop();

  scope = scope || $('body, html');

  scope.removeClass('scroll-touch');

  obj = scope ? { scrollTop: px } : { 'scroll-top': px };

  if (currScroll > px) {
    time = (currScroll - px) * options.time / 1000;
  } else {
    time = (px - currScroll) * options.time / 1000;
  }

  scope.stop().animate(obj, time, function () {
    if (callbackCalled === false) {
      callbackCalled = true;
      scope.addClass('scroll-touch');
      if (typeof callback === 'function') {
        callback();
      }
    }
  });
}