javascript, move list items up and down code example

Example: move list items up and down using javascript

window.onload = function () {
	var upLink = document.querySelectorAll(".up");

	for (var i = 0; i < upLink.length; i++) {
		upLink[i].addEventListener('click', function () {
			var wrapper = this.parentElement;

			if (wrapper.previousElementSibling)
			    wrapper.parentNode.insertBefore(wrapper, wrapper.previousElementSibling);
		});
	}

	var downLink = document.querySelectorAll(".down");

	for (var i = 0; i < downLink.length; i++) {
		downLink[i].addEventListener('click', function () {
			var wrapper = this.parentElement;

			if (wrapper.nextElementSibling)
			    wrapper.parentNode.insertBefore(wrapper.nextElementSibling, wrapper);
		});
	}
}