List<object> data = new List<object>(); data.Add(new{Id=id, Name = name});Here is full source
protected void CitiesRefresh(object sender, StoreRefreshDataEventArgs e) { XmlDocument xmlDoc = new XmlDocument(); xmlDoc.Load(HttpContext.Current.Server.MapPath("Cities.xml")); List<object> data = new List<object>(); foreach (XmlNode cityNode in xmlDoc.SelectNodes(string.Concat("countries/country[@code='", this.Countries.SelectedItem.Value, "']/city"))) { string id = cityNode.SelectSingleNode("id").InnerText; string name = cityNode.SelectSingleNode("name").InnerText; data.Add(new{Id=id, Name = name}); } this.CitiesStore.DataSource = data; this.CitiesStore.DataBind();