private void DeleteContact(object ContactsObj)
        {
            ContactsViewModel contacts = ContactsObj as ContactsViewModel;

            if (contacts != null)
            {
                Contact.Remove(contacts);
            }
            Back();
        }
        private void SaveContact(object ContactsObj)
        {
            ContactsViewModel contacts = ContactsObj as ContactsViewModel;

            if (contacts != null && contacts.IsValid)
            {
                Contact.Add(contacts);
                Back();
            }
        }