private void OnSaveCustomer()
        {
            var returnStatus = false;

            returnStatus = !IsInEditMode?CustomerAction.AddCustomer(this.DBConnectionString, this.Entity) : CustomerAction.UpdateCustomer(this.DBConnectionString, this.Entity);

            if (returnStatus)
            {
                if (RefreshCustomers != null)
                {
                    this.RefreshCustomers();
                }

                var messageDailog = new MessageDailog()
                {
                    Caption      = Resources.MessageResources.DataSavedSuccessfully,
                    DialogButton = DialogButton.Ok,
                    Title        = Resources.TitleResources.Information
                };

                MessengerInstance.Send(messageDailog);

                if (this.CloseWindow != null)
                {
                    this.CloseWindow();
                }
            }
            else
            {
                var messageDailog = new MessageDailog()
                {
                    Caption = Resources.MessageResources.DataSavedFailed, DialogButton = DialogButton.Ok, Title = Resources.TitleResources.Error
                };
                MessengerInstance.Send(messageDailog);
            }
        }