private void tsPatientBill_Click(object sender, EventArgs e)
{
if (bill == null)
{
bill = new frmPatientBills();
bill.MdiParent = this;
bill.FormClosed += new FormClosedEventHandler(bill_FormClosed);
bill.Show();
}
else
{
bill.Activate();
bill.WindowState = FormWindowState.Normal;
}
}
void bill_FormClosed(object sender, FormClosedEventArgs e)
{
bill = null;
}
