public void showFragmentNoBackStack(String fragmentTag, Object dataForFragment) {
                showFragment(fragmentTag, dataForFragment, false);
        }

public void showFragmentAddToBackStack(String fragmentTag, Object dataForFragment) {
                showFragment(fragmentTag, dataForFragment, true);
        }

public void showFragment(String fragmentTag, Object object, Boolean addToBackStack) {

            FragmentManager fragmentManager = getSupportFragmentManager();
            FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();

     switch (fragmentTag) {
                case SIMPLE_SEARCH_FRAGMENT_TAG:
                    fragment = new SimpleSearchFragment();
                    break;

                case ADVANCED_SEARCH_FRAGMENT_TAG:
                    fragment = new MultiSearchFragment();
                    break;
    }
            fragmentTransaction.replace(R.id.main_activity_container, fragment);

        if (addToBackStack)
                fragmentTransaction.addToBackStack(null);

            fragmentTransaction.commit();
}

@Override
    public void onBackPressed() {        if (getSupportFragmentManager().getBackStackEntryCount() > 0) {
            getSupportFragmentManager().popBackStack();
        } else {
            finish();
        }
    }

@Override
public void onBackPressed() {
    if (getFragmentManager().getBackStackEntryCount() > 0) {
        getFragmentManager().popBackStack();
    } else {
        super.onBackPressed();
    }
}