private void counterBttn_Click(object sender, EventArgs e)
{
if (counterform == null)
{
counterform = new counterFrm();
counterform.Tag = username1;
counterform.FormClosed += counterform_FormClosed;
}
counterform.Show(this);
Hide();
}
void counterform_FormClosed(object sender, FormClosedEventArgs e)
{
counterform = null;
Show();
}