private void OnAdaugaFacturaFormValidation(object sender, EventArgs e)
        {
            switch (ValidateAdaugaFacturaMenuItemForm())
            {
            case AdaugaFacturaFormValidation.ADAUGAFACTURA_FORM_VALID:
                View.ValidationFormValid();
                break;

            case AdaugaFacturaFormValidation.ADAUGAFACTURA_FORM_INPUTS_EMPTY:
                View.ValidateInputsEmpty();
                break;

            case AdaugaFacturaFormValidation.ADAUGAFACTURA_FORM_NEGATIVE_NULL_VALUES:
                View.ValidationNegativeOrNullValues();
                break;

            case AdaugaFacturaFormValidation.ADAUGAFACTURA_FORM_LENGTH_NOT_OK:
                View.ValidateInputLengthNotOk();
                break;

            case AdaugaFacturaFormValidation.ADAUGAFACTURA_FORM_INPUTS_MISSING:
                View.ValidateInputsMissing();
                break;

            default:
                //should not be reached
                break;
            }
        }