???

while(myReader.Read())
{
  bookdetails  bookde=new bookdetails();
       bookde.bookname=myReader.GetString(0);
                   bookde.bookcode=myReader.GetString(1);
                   bookde.namecode=myReader.GetString(2);
       bookde.isbn=myReader.GetString(3);
                 bookde.booknum=myReader.GetInt16(4); }