private void deletebtn_Click(object sender, EventArgs e)
{
if (D == null)
{
D = new deleteitem();
D.FormClosed += new FormClosedEventHandler(D_FormClosed);
D.Show();
}
else
{
D.Activate();
}
}
void D_FormClosed(object sender, FormClosedEventArgs e)
{
D = null;
}