private void bttn_newEntry_Click(object sender, EventArgs e)
        {
            if (selectedPatient != null)
            {
                List <Patient> choices = new List <Patient>(); // So the user doesn't need to look through a long dropdown
                choices.Add(selectedPatient);

                using (var formTreatment = new FrmTreatment(choices))
                {
                    var result = formTreatment.ShowDialog();

                    if (result == DialogResult.OK)
                    {
                        treatments = Databasemanager.GetTreatments(selectedPatient.Id);
                        fillTreatmentList(treatments);
                    }
                }
            }
            else
            {
                using (var formTreatment = new FrmTreatment(allPatients))
                {
                    var result = formTreatment.ShowDialog();
                }
            }
        }
        private void bttn_editEntry_Click(object sender, EventArgs e)
        {
            if (selectedTreatment != null)
            {
                List <Patient> choices = new List <Patient>(); // So the user doesn't need to look through a long dropdown
                choices.Add(selectedPatient);

                using (var formTreatment = new FrmTreatment(choices, selectedTreatment))
                {
                    var result = formTreatment.ShowDialog();

                    if (result == DialogResult.OK)
                    {
                        treatments = Databasemanager.GetTreatments(selectedPatient.Id);
                        fillTreatmentList(treatments);
                    }
                }
            }
            else
            {
                MessageBox.Show("Um die Behandlungsdaten einer bestehenden Behandlung zu bearbeiten, müssen sie zunächst eine Behandlung auswählen.");
            }
        }