@Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case android.R.id.home:
                // This ID represents the Home or Up button. In the case of this
                // activity, the Up button is shown. Use NavUtils to allow users
                // to navigate up one level in the application structure. For
                // more details, see the Navigation pattern on Android Design:
                //
                // http://developer.android.com/design/patterns/navigation.html#up-vs-back
                //
                NavUtils.navigateUpTo(this, new Intent(this, ItemListActivity.class));
                return true;
        }
        return super.onOptionsItemSelected(item);
    }
An activity representing a single Item detail screen. This activity is only
used on handset devices. On tablet-size devices, item details are presented
side-by-side with a list of items in a {@link ItemListActivity}.
<p>
This activity is mostly just a 'shell' activity containing nothing more than
a {@link ItemDetailFragment}.

@author Tonic Artos
Example/src/com/tonicartos/stickygridheadersexample/ItemDetailActivity.java