private void BtnNewInvoice_Click(object sender, EventArgs e)
{
newInvForm = new NewInvoiceForm(InvoiceType.Arrival);
newInvForm.ShowDialog();
}
private void button1_Click(object sender, EventArgs e)
{
newInvForm = new NewInvoiceForm(InvoiceType.Production);
newInvForm.ShowDialog();
}