@Override
 public void onPageSelected(int position) {
   MainActivity.FIRST_PAGE = position;
   Log.i("TEST ADAPTER", MainActivity.FIRST_PAGE + "");
   if (position == MainActivity.maxPeople - 1) {
     btn.setText("+ New RECEIVER");
     vp.setPagingEnabled(false);
     vp.setPagingMax(true);
   } else {
     btn.setText("SELECT");
     vp.setPagingMax(false);
   }
 }
 private String getFragmentTag(int position) {
   return "android:switcher:" + vp.getId() + ":" + position;
 }