private void DeclineButton_Click(object sender, EventArgs e)
 {
     if (New)
     {
         NameTextbox.Text     = "";
         CodenameTextbox.Text = "";
     }
     else if (CustomMessages.YesNoDelete(this))
     {
         Deleted = controller.Delete(subject);
         if (!Deleted)
         {
             CustomMessages.DeleteFail(this, "subject");
         }
         Close();
     }
 }
 private void DeclineButton_Click(object sender, EventArgs e)
 {
     if (New)
     {
         BuildingTextbox.Text     = "";
         FloorNumericUpdown.Value = 0;
         RoomTextbox.Text         = "";
     }
     else if (CustomMessages.YesNoDelete(this))
     {
         Deleted = controller.Delete(hall);
         if (!Deleted)
         {
             CustomMessages.DeleteFail(this, "lecture hall");
         }
         Close();
     }
 }