how can i change the whole layout in list view to checkboxlist view i m using the service that is servelet based but here is the code plese fix it up.?

private ListView machine_listview;
      ArrayAdapter<String> adapter;
      ArrayList<String> arrayListofMachines;
      ArrayList<String> arrayListofMachineNumbers;
      Vector<MDCMachineStatus> machineStatus_vector;
      Handler handler;

      private static int oldPosition = 0;
      private Boolean firstClick = true;

      @Override
      protected void onCreate(Bundle savedInstanceState) {
          // TODO Auto-generated method stub
          super.onCreate(savedInstanceState);
          setContentView(R.layout.machinelistview);

          machine_listview = (ListView) findViewById(R.id.machine_listview);
          machine_listview.setFastScrollEnabled(true);

          MachineStatusSingleton.Register(this);

          getData();

          adapter = new ArrayAdapter<String>(MachineListView.this, R.layout.listviewrow, arrayListofMachines);

  //      adapter = new ArrayAdapter<String>(this, R.layout.listviewrow, arrayListofMachines);
          machine_listview.setAdapter(adapter);

          machine_listview.setSelection(oldPosition);

  //      adapter = new Arr
          machine_listview.setOnItemClickListener(new OnItemClickListener() {

              public void onItemClick(AdapterView<?> arg0, View arg1, int position,
                      long arg3) {
                  // TODO Auto-generated method stub
                  oldPosition = position;
                  MachineStatusSingleton.setMachineNumber(arrayListofMachineNumbers.get(position));
                  MachineListView.this.finish();


              }
          });

          handler = new Handler(){
              public void handleMessage(android.os.Message msg) {
                  machine_listview.setAdapter(adapter);
                  adapter.notifyDataSetChanged();
              };
          };
      }
      public void Update(ISubject arg0) {
          // TODO Auto-generated method stub
  //      updateData();
      }

      @Override
      public void onDestroy()
      {
          super.onDestroy();

          MachineStatusSingleton.Unregister(this);
      }

      private void getData(){
          machineStatus_vector = MachineStatusSingleton.GetData();
          arrayListofMachines = new ArrayList<String>();
          arrayListofMachineNumbers = new ArrayList<String>();
          for(MDCMachineStatus temp: machineStatus_vector){
              arrayListofMachines.add(temp.toString());
              arrayListofMachineNumbers.add(temp.getNumber());
          }

          Collections.sort(arrayListofMachines);
          Collections.sort(arrayListofMachineNumbers);

      }

      private void updateData(){
          getData();

          handler.sendEmptyMessage(0);
  //      machine_listview.postInvalidate();
          adapter.notifyDataSetChanged();
          int index = machine_listview.getFirstVisiblePosition();
          View v = machine_listview.getChildAt(0);
          int top = (v == null) ? 0 : v.getTop();

          // ...

          // restore
          machine_listview.setSelectionFromTop(index, top);
  //      adapter.notifyDataSetChanged();
      }


  }