private void invoiceListToolStripMenuItem_Click(object sender, EventArgs e)
{
if (_instanceInvoiceMaster == null)
{
CloseAllForms();
_instanceInvoiceMaster = new Invoice.InvoiceMaster();
_instanceInvoiceMaster.MdiParent = this;
_instanceInvoiceMaster.FormClosed += instanceInvoiceMasterHasBeenClosed;
}
else
{
ShowMessage();
}
_instanceInvoiceMaster.Show();
}
private void instanceInvoiceMasterHasBeenClosed(object sender, FormClosedEventArgs e)
{
_instanceInvoiceMaster = null;
}
