onListItemClick이 클릭에 응답하지 않습니다.

내 onListItemClick에 문제가 있습니다.

이것은 내 Menu.java 클래스입니다 .

public class Menu extends ListActivity{

String classes[] = { "MainActivity", "etcetera1", "etcetera2", "etcetera3", "etcetera4", "etcetera5"};

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setListAdapter(new ArrayAdapter<String>(Menu.this, android.R.layout.simple_list_item_1, classes));
}

@SuppressWarnings("rawtypes")
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {

    // TODO Auto-generated method stub
    super.onListItemClick(l, v, position, id);
    String positie = classes[position];
    try{
    Class ourClass = Class.forName("com.jacob.eindproject.MAIN" + positie);
    Intent ourIntent = new Intent(Menu.this, ourClass);
    startActivity(ourIntent);
    }catch (ClassNotFoundException e){
        e.printStackTrace();
    }
}

그리고 이것은 나의 MainActivity 클래스입니다 (BMI 계산기입니다.).

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate het menu
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }


     public void calculateClickHandler(View view) {
         // handeld het klikken op de button

         if (view.getId() == R.id.berekenButton) {

          // referenties
          EditText gewichtText = (EditText)findViewById(R.id.gewichtText);
          EditText lengteText = (EditText)findViewById(R.id.lengteText);
          TextView resultaat = (TextView)findViewById(R.id.resultaat);

          // waarden

          float gewicht = Float.parseFloat(gewichtText.getText().toString());
          float lengte = Float.parseFloat(lengteText.getText().toString());

          // berekend de BMI

          float bmiWaarde = berekenBMI(gewicht, lengte);

          // zoekt de bijbehorende label (overgewicht etc.)
          String bmiInterpretation = interpretBMI(bmiWaarde);

          // weergeeft het resultaat

          resultaat.setText(bmiWaarde + "-" + bmiInterpretation);
         }
        }

        // de formule

        private float berekenBMI (float gewicht, float lengte) {

         return (float) (gewicht / (lengte * lengte));
        }


        // bijbehorende labels:
        private String interpretBMI(float bmiWaarde) {

         if (bmiWaarde < 16) {
          return "Ernstig Ondergewicht";
         } 

         else if (bmiWaarde < 18.5) {

          return "Ondergewicht";
         }

         else if (bmiWaarde < 25) {

          return "Normaal";
         }

         else if (bmiWaarde < 30) {

          return "Overgewicht";
         }

         else {
          return "Obees";
         }

        }
    }

에뮬레이터를 시작하면 목록 항목을 클릭해도 응답하지 않습니다. 누군가 아이디어? 예,이 웹 사이트에서 모든 관련 질문을 확인했습니다.

편집 : (main.xml)

<menu xmlns:android="http://schemas.android.com/apk/res/android" >

<item
    android:id="@+id/aboutUs"
    android:title="@+id/About"/>

    <item
    android:id="@+id/instellingen"
    android:title="@+id/Instellingen"/>