Import XML to object list

[T@MeR]

I am currently experiencing an issue trying to import my XML elements into a list of type Books. I am receiving an 'Object reference not set to an instance of an object' error on this piece of code:\[code\]mybook.Title = p.Element("title").Value;\[/code\]Am I referencing the XML element improperly or is it some other simple matter? I have googled for hours on end through endless solutions and topics and can not get over this last hurdle.For simplicity, here is the code in one file:\[code\]class Program{ static void Main(string[] args) { string appPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location); FileInfo fi = new FileInfo(Path.Combine(appPath, "Books.xml")); Console.WriteLine(GetBooks()); } public class Books { public string ID { get; set; } public string Name { get; set; } public string Title { get; set; } public decimal Price { get; set; } public DateTime PublishDate { get; set; } public string Description { get; set; } } public static List<Books> GetBooks() { XDocument doc = LinqToXml.XmlHelper.GetPlantDocument(); var xmlBooks = doc.Descendants("catalog"); List<Books> someBooks = new List<Books>(); foreach (var p in xmlBooks) { Books mybook = new Books(); mybook.Title = p.Element("title").Value; someBooks.Add(mybook); } return someBooks; }}\[/code\]This is the contents of the XML file:http://pastebin.com/ZVmWqRT1Please note that this is indeed a homework project. I am not looking for a direct answer necessarily as I am a giant hint or two.