private void randevuEkranıToolStripMenuItem_Click(object sender, EventArgs e)
 {
     if (randevuEkrani == null || randevuEkrani.IsDisposed)
     {
         randevuEkrani = new RandevuEkrani();
         randevuEkrani.MdiParent = this;
         randevuEkrani.Dock = DockStyle.Fill;
         randevuEkrani.Show();
     }
 }
 private void AcilisEkrani_Load(object sender, EventArgs e)
 {
     if (randevuEkrani == null || randevuEkrani.IsDisposed)
     {
         randevuEkrani = new RandevuEkrani();
         randevuEkrani.MdiParent = this;
         randevuEkrani.Dock = DockStyle.Fill;
         randevuEkrani.Show();   
     }
 }