Get all list items using ECMAscript SharePoint 2010

<script src="/_layouts/SP.js" type="text/ecmascript"></script>
<script type="text/javascript">

function ViewItem()
{
var context = new SP.ClientContext.get_current();
var web = context.get_web();
var list = web.get_lists().getByTitle('Testlist');

var query = SP.CamlQuery.createAllItemsQuery();
allItems = list.getItems(query);
context.load(allItems, 'Include(Title,Department)');

context.executeQueryAsync(Function.createDelegate(this, this.success), Function.createDelegate(this, this.failed));
}

function success() {

var TextFiled = "";
var ListEnumerator = this.allItems.getEnumerator();

while(ListEnumerator.moveNext())
{
var currentItem = ListEnumerator.get_current();
TextFiled  += currentItem.get_item('Title') + '-' +currentItem.get_item('Department') + '\n';
}
alert(TextFiled);
}

function failed(sender, args) {
alert("failed. Message:" + args.get_message());
}

</script>