a native scrollTo function in javascript that uses requestAnimationFrame and easing for animation

scrollTo.js

// easing functions http://goo.gl/5HLl8
Math.easeInOutQuad = function (t, b, c, d) {
  //t = current time
  //b = start value
  //c = change in value
  //d = duration
  t /= d/2;
  if (t < 1) {
    return c/2*t*t + b
  }
  t--;
  return -c/2 * (t*(t-2) - 1) + b;
};

function scrollTo(element, to, duration) {
  var start = element.scrollTop,
  change = to - start,
  currentTime = 0,
  increment = 20;
  var animateScroll = function(){
    // increment the time
    currentTime += increment;
    // find the value with the quadratic in-out easing function
    var val = Math.easeInOutQuad(currentTime, start, change, duration);
    // move the element
    element.scrollTop = val;
    // do the animation unless its over
    if(currentTime < duration) {
      setTimeout(animateScroll, increment);
    }
  };
  animateScroll();
}
// scrollTo(document.body, 0, 500);