public void move_to_another_fragment() {
    Fragment fragment = (Fragment) new ItemFragment();
    FragmentManager fragmentManager = getFragmentManager();
    getActivity().getActionBar().setTitle("Items");
    fragmentManager.beginTransaction()
        .replace(R.id.frame_container, fragment)
        .addToBackStack("invoiceinfo").commit();

}

FragmentManager fm = getActivity().getFragmentManager();
fm.beginTransaction().addToBackStack("purchase_order");
fm.popBackStack();

FragmentManager fm = getActivity().getFragmentManager();
fm.beginTransaction().addToBackStack("purchase_order");
fm.popBackStack();

FragmentManager fm = getActivity().getFragmentManager();
            fm.popBackStackImmediate();

FragmentManager fm = getActivity()
                .getSupportFragmentManager();
        fm.popBackStack ("invoiceinfo", FragmentManager.POP_BACK_STACK_INCLUSIVE);