private void button4_Click(object sender, EventArgs e)
        {
            var mediaSharingForm = new MediaSharingForm();

            mediaSharingForm.Show();
            this.Hide();
        }
 private void AutomatischeDoorverbinding()
 {
     if (administratie.NuIngelogd is Controleur)
     {
         var toegangsControleForm = new Toegangscontroleform();
         toegangsControleForm.Show();
         this.Hide();
     }
     else if (administratie.NuIngelogd is Bezoeker)
     {
         var mediaSharingForm = new MediaSharingForm();
         mediaSharingForm.Show();
         this.Hide();
     }
 }