private void viewStatisticsToolStripMenuItem_Click(object sender, EventArgs e)
 {
     if (_stats == null)
     {
         _stats = new FrmVoteStatistics() { MdiParent = this };
         _stats.FormClosed += Stats_FormClosed;
         _stats.Show();
     }
     else
     {
         _stats.Activate();
         _stats.WindowState = FormWindowState.Normal;
     }
 }
 private void Stats_FormClosed(object sender, FormClosedEventArgs e)
 {
     _stats = null;
 }