simplerxml.cs

 [XmlType(Namespace = "urn:ebay:apis:eBLBaseComponents")]
    public class Order
    {
        public string OrderID { get; set; }
        public string OrderStatus { get; set; }
    }

    [XmlType(Namespace = "urn:ebay:apis:eBLBaseComponents")]
    public class OrderArray
    {
        public Order Order { get; set; }
    }

    [XmlRoot(Namespace = "urn:ebay:apis:eBLBaseComponents")]
    public class GetOrdersResponse
    {
        public string Timestamp { get; set; }
        public string Ack { get; set; }
        public string Version { get; set; }
        public string Build { get; set; }
        public OrderArray OrderArray { get; set; }
    }