private void AddSubject_Click(object sender, EventArgs e)
        {
            string name = FindViewById <EditText>(Resource.Id.dean_newSubject_name).Text;

            if (DataBaseHelper.IsServerAlive())
            {
                DataBaseHelper.AddNewSubgect(name);
                Toast.MakeText(this, "New subject is added!", ToastLength.Long).Show();
            }
            else
            {
                Toast.MakeText(this, "Server isn't alive", ToastLength.Long).Show();
            }
            Finish();
        }