// This Constructor is used for FileFandler
 public Book(String item, String serialNumber, String type,
             String titname, String author, String price, Date ed_pubDate, String stock,
             String numPages, String genre) :
     base(item, serialNumber, type, titname, author, price,
          ed_pubDate, stock)
 {
     this.numPages = Convert.ToInt16(numPages);
     this.genre    = (EnumBookGenre)Enum.Parse(typeof(EnumBookGenre), genre);
 }
 public Book(int item, string serialNumber, EnumProdType type,
             string titname, string author, Double price, Date ed_pubDate,
             int stock,
             int numPages, EnumBookGenre genre) :
     base(item, serialNumber, type, titname, author, price,
          ed_pubDate, stock)
 {
     this.numPages = numPages;
     this.genre    = genre;
 }
 public Book(int numPages, EnumBookGenre genre)
 {
     this.numPages = numPages;
     this.genre    = genre;
 }