private void BtnIstatistik_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
 {
     if (fr4 == null || fr4.IsDisposed)
     {
         fr4           = new Formlar.FrmIstatistik();
         fr4.MdiParent = this;
         fr4.Show();
     }
 }
 private void BtnIstatistik_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
 {
     Formlar.FrmIstatistik fr = new Formlar.FrmIstatistik();
     fr.MdiParent = this;
     fr.Show();
 }