smooth-scroll-to.js

// usage smoothScrollTo.call([NodeElement])
function smoothScrollTo(completeCallback) {
	// center element on screen
	var posY = window.pageYOffset - (window.innerHeight / 2) +  this.getBoundingClientRect().top + (this.offsetHeight / 2);

	scrollAnimator = TweenLite.to(window, 1, {
		scrollTo: {
			y: posY
		},
		onComplete: function(){
			if(typeof completeCallback === 'function')
				completeCallback();
		},
		ease: Quint.easeInOut
	});
}