void udi_FormClosed(object sender, FormClosedEventArgs e)
{
udi = null;
}
private void updateADepartmentInformationToolStripMenuItem_Click(object sender, EventArgs e)
{
if (udi == null)
{
udi = new UpdateDepartmentInfo();
udi.MdiParent = this;
udi.FormClosed += udi_FormClosed;
udi.Show();
}
else
{
udi.Activate();
}
}