static void ViewMap_Click(object sender, EventArgs e)
{
if (_form != null)
{
_form.Close();
}
_form = new MouseHeatMapForm();
_form.Points = _dictionary;
_form.Show();
_form.FormClosed += new FormClosedEventHandler(_form_FormClosed);
}
static void _form_FormClosed(object sender, FormClosedEventArgs e)
{
_form.Dispose();
_form = null;
}