static void Main(string[] args)
        {
            Console.WriteLine("***Welcome_To_AddressBookSystem_Linq***");
            AddressBookModel     model        = new AddressBookModel();
            AddressBookDataTable adddataTable = new AddressBookDataTable();

            adddataTable.CreateTable(model);

            while (true)
            {
                Console.WriteLine("\nEnter Choice  \n1. Add Contact \n2. Display \n3. Edit Contact  \n4. DeletContact \n5. ContactFrom_City \n6. ContactsFrom_State \n7. CountByCityOrState \n8. Sort_Contacts\n9. CountBy_AddressBook_Type \n10. Exit ");
                int choice = Convert.ToInt32(Console.ReadLine());
                try
                {
                    switch (choice)
                    {
                    case 1:
                        Console.Write("Enter the first name: ");
                        model.First_Name = Console.ReadLine();
                        Console.Write("Enter the last name :");
                        model.Last_Name = Console.ReadLine();
                        Console.Write("Enter the Address : ");
                        model.Address = Console.ReadLine();
                        Console.Write("Enter the city : ");
                        model.City = Console.ReadLine();
                        Console.Write("Enter the state :");
                        model.State = Console.ReadLine();
                        Console.Write("Enter the zip code : ");
                        model.Zip = Console.ReadLine();
                        Console.Write("Enter the phone number : ");
                        model.Phone_Number = Console.ReadLine();
                        Console.Write("Enter the E-mail : ");
                        model.Email = Console.ReadLine();
                        adddataTable.AddContact(model);
                        break;

                    case 2:
                        adddataTable.Display();
                        break;

                    case 3:
                        Console.Write("Enter the first name: ");
                        model.First_Name = Console.ReadLine();
                        Console.Write("Enter the last name :");
                        model.Last_Name = Console.ReadLine();
                        Console.Write("Enter the Address : ");
                        model.Address = Console.ReadLine();
                        Console.Write("Enter the city : ");
                        model.City = Console.ReadLine();
                        Console.Write("Enter the state :");
                        model.State = Console.ReadLine();
                        Console.Write("Enter the zip code : ");
                        model.Zip = Console.ReadLine();
                        Console.Write("Enter the phone number : ");
                        model.Phone_Number = Console.ReadLine();
                        Console.Write("Enter the E-mail : ");
                        model.Email = Console.ReadLine();
                        adddataTable.EditContact(model);
                        break;

                    case 4:
                        Console.Write("Enter First Name: ");
                        model.First_Name = Console.ReadLine();
                        adddataTable.DeleteContact(model);
                        break;

                    case 5:
                        Console.WriteLine("Enter the city :");
                        model.City = Console.ReadLine();
                        adddataTable.RetrievePersonByUsingCity(model);
                        Console.WriteLine("Contacts_From_City");
                        break;

                    case 6:
                        Console.WriteLine("Enter the State : ");
                        model.State = Console.ReadLine();
                        adddataTable.RetrievePersonByUsingState(model);
                        Console.WriteLine("Contacts_From_State");
                        break;

                    case 7:
                        adddataTable.CountByCityAndState();
                        break;

                    case 8:
                        Console.WriteLine("Enter the city: ");
                        model.City = Console.ReadLine();
                        adddataTable.SortContactAlphabeticallyForGivenCity(model);
                        break;

                    case 9:
                        adddataTable.GetCountByAddressBookType();
                        break;

                    case 10:
                        Environment.Exit(0);
                        break;

                    default:
                        Console.WriteLine("Invalid option...");
                        break;
                    }
                }
                catch
                {
                    Console.WriteLine("please enter integer options only");
                }
            }
        }
 public void AddContact(AddressBookModel model)
 {
     dataTable.Rows.Add(model.First_Name, model.Last_Name, model.Address, model.City,
                        model.State, model.Zip, model.Phone_Number, model.Email);
     Console.WriteLine("Contact Added Succesfully...");
 }