private void BtnBack_Click(object sender, EventArgs e)
        {
            string            message = "Apasa DA daca doresti sa salvezi toate modificarile facute. Apasa Nu daca doresti sa nu salvezi nimic";
            string            title   = "Atentie";
            MessageBoxButtons buttons = MessageBoxButtons.YesNo;
            InvoiceModel      invoice = new InvoiceModel()
            {
                invoiceId       = invoiceIdSelected,
                invoiceNumber   = txtNrInvoice.Text,
                invoiceDate     = dateTimePickerInvoiceDate.Value,
                clientId        = 0,
                clientName      = comboBoxClientName.Text,
                clientAddressId = 0,
                clientAddress   = comboBoxClientAddress.Text,
                userId          = LoginForm.id,
                observations    = txtObs.Text,
                status          = this.statusInv
            };

            if (!IsModify())
            {
                DialogResult result = MessageBox.Show(message, title, buttons, MessageBoxIcon.Information);
                if (result == DialogResult.No)
                {
                    iform.Show();
                    this.Hide();
                }
                else
                {
                    if (BasicValidation() == false)
                    {
                        return;
                    }
                    SaveInvoice();

                    iform.UpdateDataGridView(invoice);
                    iform.Show();
                    this.Hide();
                }
            }
            else
            {
                iform.UpdateDataGridView(invoice);
                iform.Show();
                this.Hide();
            }
        }
        private void BtnInvoice_Click(object sender, EventArgs e)
        {
            InvoiceListForm invoice = new InvoiceListForm();

            invoice.Show();
            this.Hide();
            invoice.FormClosed += Invoice_FormClosed;
        }