js file

<script>
"use strict";
var list = {};

function generateList() {
	var listItems = document.getElementsByTagName("li");
	for (var i = listItems.length - 1; i >= 0; i--) {
		document.getElementsByTagName("ol")[0].removeChild(listItems[i]);
	}
	for (var i = 0; i < list.length; i++;) {
		var newItem = "<span class='first'>first</span>" + list[i];
		var newListItem = document.createElement("li");
		newListItem.innerHTML = newItem;
		document.getElementsByTagName("ol")[0].appendChild(newListItem);
		var firstButtons = document.querySelectorAll(".first");
		var lastFirstButton = firstButtons[firstButtons.length - 1];
		if (lastFirstButton.addEventListener) {
			lastFirstButton.addEventListener("click", moveToTop, false);
		} else if (lastFirstButton.attachEvent) {
			lastFirstButton.attachEvent("onclick", moveToTop);
		}
	}
}

function addItem() {
	var newItem = document.getElementById("newItem");
	list.push(newItem.value);
	newItem.focus();
	newItem.value = "";
	generateList();
}

function moveToTop() {
	if (evt === undefined) {
		// get caller element in IE8
		evt = window.event;
	}
	var callerElement = evt.target || evt.srcElement;
	var listItems = document.getElementsByTagName("li");
	var parentItem = callerElement.parentNode;
	for (var i = 0; i < list.length; i++) {
		if (parentItem.innerHTML.search(list[i]) !== -1) {
			var itemToMove = list.splice(i, 1);
			list.unshift(itemToMove);
		}
	}
	generateList();
}

function createEventListener() {
	var addButton = document.getElementById("button");
	if (addButton.addEventListener) {
		addButton.addEventListener("click", addItem, false);
	} else if (addButton.attachEvent) {
		addButton.attachEvent("onclick", addItem);
	}
}

if (window.addEventListener) {
	window.addEventListener("load", createEventListener, false);
} else if (window.attachEvent) {
	window.attachEvent("onload", createEventListener);
}
</script>