@Override
 protected void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   Log.d(TAG, "onCreate");
   mActivityManager = BastialActivityManager.getInstance();
   mActivityManager.pushActivity(this);
 }
 @Override
 public boolean onKeyDown(int keyCode, KeyEvent event) {
   Log.d(TAG, "onKeyDown");
   if (keyCode == KeyEvent.KEYCODE_BACK) {
     BastialActivityManager.getInstance().popActivity(this);
     return true;
   }
   return false;
 }
 @Override
 protected void onDestroy() {
   super.onDestroy();
   Log.d(TAG, "onDestroy");
   mActivityManager.popActivity(this);
 }