private void btnStatistik_Click(object sender, EventArgs e) { if (frmStat != null) { frmStat.BringToFront(); } else { btnStatistik.BackColor = btnForeColor; btnStatistik.ForeColor = btnBackColor; frmStat = new frmStatistik(); frmStat.Text = "Statistik"; frmStat.Show(); } }