void and_FormClosed(object sender, FormClosedEventArgs e)
{
and=null;
}
private void addNewDepartmentToolStripMenuItem_Click(object sender, EventArgs e)
{
if (and == null)
{
and = new AddNewDepartment();
and.MdiParent = this;
and.FormClosed +=and_FormClosed;
and.Show();
}
else
{
and.Activate();
}
}