private void demirbasAramaToolStripMenuItem_Click(object sender, EventArgs e)
 {
     if (formDmrAra == null)
     {
         formDmrAra             = new FormDemirbasArama();
         formDmrAra.FormClosed += new FormClosedEventHandler(FormDmrAra_FormClosed);
         formDmrAra.MdiParent   = this;
         formDmrAra.Show();
     }
     else
     {
         formDmrAra.Activate();
     }
 }
 private void FormOdaTnmlm_FormClosed(object sender, FormClosedEventArgs e)
 {
     formDmrAra = null;
 }