public void SaveAdministratorExecute()
 {
     if (String.IsNullOrEmpty(ClinicAdministrator.NameAndSurname) || String.IsNullOrEmpty(ClinicAdministrator.IdentityCardNumber) || String.IsNullOrEmpty(ClinicAdministrator.DateOfBirth.ToString()) || String.IsNullOrEmpty(ClinicAdministrator.Gender) ||
         String.IsNullOrEmpty(ClinicAdministrator.Citizenship) || String.IsNullOrEmpty(ClinicAdministrator.Username) || String.IsNullOrEmpty(ClinicAdministrator.Password))
     {
         MessageBox.Show("Please fill all fields.", "Notification");
     }
     else
     {
         try
         {
             MessageBoxResult result = MessageBox.Show("Are you sure you want to save the administrator?", "Confirmation", MessageBoxButton.YesNo, MessageBoxImage.Question);
             if (result == MessageBoxResult.Yes)
             {
                 bool isCreated = administrators.CreateAdministrator(ClinicAdministrator);
                 if (isCreated)
                 {
                     MessageBox.Show("Administrator is created.", "Notification", MessageBoxButton.OK);
                     administratorView.Close();
                 }
                 else
                 {
                     MessageBox.Show("Administrator cannot be created.", "Notification", MessageBoxButton.OK);
                 }
             }
         }
         catch (Exception ex)
         {
             MessageBox.Show(ex.ToString());
         }
     }
 }