private void updateScore(String username, int score) {
   String url = "http://203.151.92.187:8080/updateAssignmentScore";
   String param =
       "sessionId="
           + URLEncoder.encode(SingletonID.getInstance().getSessionId())
           + "&courseId="
           + URLEncoder.encode(courseId)
           + "&username="******"&title="
           + URLEncoder.encode(title)
           + "&score="
           + URLEncoder.encode(String.valueOf(score));
   String result = "Fail";
   try {
     HttpPostConnection httpPostConnection = new HttpPostConnection();
     httpPostConnection.execute(url, param);
     String strJson = httpPostConnection.get();
     JSONObject jsonObject = new JSONObject(strJson);
     result = jsonObject.getString("status");
   } catch (ExecutionException e) {
     e.printStackTrace();
   } catch (InterruptedException e) {
     e.printStackTrace();
   } catch (JSONException e) {
     e.printStackTrace();
   }
   Toast.makeText(getApplicationContext(), result, Toast.LENGTH_SHORT).show();
 }
  private void createList() {
    stdName = new ArrayList<String>();
    stdUser = new ArrayList<String>();
    String url = "http://203.151.92.187:8080/viewEnrolledStudents";
    String param = "courseId=" + URLEncoder.encode(courseId);
    try {
      HttpPostConnection httpPostConnection = new HttpPostConnection();
      httpPostConnection.execute(url, param);
      String strJson = httpPostConnection.get();
      JSONArray jsonArray = new JSONArray(strJson);
      for (int i = 0; i < jsonArray.length(); i++) {
        JSONObject jsonObject = jsonArray.getJSONObject(i);
        String stdId = jsonObject.getString("studentId");
        String name = jsonObject.getString("firstName") + " " + jsonObject.getString("lastName");
        String user = jsonObject.getString("username");
        Log.i("Test", user + " " + " " + stdId + " " + name);

        stdName.add(stdId + " " + name);
        stdUser.add(user);
      }
    } catch (ExecutionException e) {
      e.printStackTrace();
    } catch (InterruptedException e) {
      e.printStackTrace();
    } catch (JSONException e) {
      e.printStackTrace();
    }

    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, R.layout.list_layout, stdName);

    final ListView listview = (ListView) findViewById(R.id.listView);
    listview.setAdapter(adapter);

    listview.setOnItemClickListener(
        new AdapterView.OnItemClickListener() {
          @Override
          public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            show(stdUser.get(position));
          }
        });
  }