private void BtnAdd_Click(object sender, EventArgs e)
        {
            InvoiceRowForm ivf = new InvoiceRowForm(0, this, 0);

            ivf.GetInitialValue();
            FormState.PreviousPage = this;
            ivf.Show();
            this.Hide();
        }
        private void BtnSave_Click(object sender, EventArgs e)
        {
            if (BasicValidation())
            {
                invoiceDetail.invoiceDetailId = invoiceDetailId;
                invoiceDetail.invoiceId       = invoiceId;
                foreach (ItemModel item in list)
                {
                    if (item.itemName == comboBoxItem.Text)
                    {
                        invoiceDetail.itemId = item.itemId;
                    }
                }

                invoiceDetail.itemName    = comboBoxItem.Text;
                invoiceDetail.qtty        = Convert.ToDecimal(txtQtty.Text);
                invoiceDetail.price       = Convert.ToDecimal(txtPrice.Text);
                invoiceDetail.amount      = Convert.ToDecimal(txtAmount.Text);
                invoiceDetail.observation = txtObs.Text;
                invoiceDetail.status      = status;
                if (this.unique == "")
                {
                    invoiceDetail.unique = invoiceDetail.RandomString(8);
                }
                else
                {
                    invoiceDetail.unique = this.unique;
                }


                isAdded = false;
                invoiceAddForm.AddItemToDataGridViewAndList(this);
                invoiceAddForm.Show();
                this.Hide();
            }
        }
        private void BtnEdit_Click(object sender, EventArgs e)
        {
            if (dataGridViewInvoice.Rows.Count != 0)
            {
                int      i = dataGridViewInvoice.SelectedCells[0].RowIndex;
                int      selectedInvoiceId = Convert.ToInt32(dataGridViewInvoice.Rows[i].Cells[0].Value.ToString());
                DateTime date = Convert.ToDateTime(dataGridViewInvoice.Rows[i].Cells[2].Value.ToString());

                InvoiceRowForm iv = new InvoiceRowForm(selectedInvoiceId, this, 1);
                iv.InvoicePopulateForm(date);
                iv.GetInitialValue();
                FormState.PreviousPage = this;
                iv.Show();
                this.Hide();
            }
            else
            {
                MessageBox.Show("Nu exista nicio factura pentru editare", "Atentie", MessageBoxButtons.OK, MessageBoxIcon.Information);
                return;
            }
        }