private void Clear()
{
TxtCustomerName.Clear();
TxtCustomerSurname.Clear();
TxtCustomerPhone.Clear();
TxtCustomerEmail.Clear();
TxtCustomerIdNumber.Clear();
}
// TextBox Reset
private void Reset()
{
TxtCustomerName.Clear();
TxtCustomerPhone.Clear();
TxtCustomerSurname.Clear();
DtpBirthday.SelectedDate = null;
BtnCreate.Visibility = Visibility.Visible;
BtnUpdate.Visibility = Visibility.Hidden;
BtnDelete.Visibility = Visibility.Hidden;
FillCustomers();
}