android.support.v4.app.Fragment.mFragmentManager' on a null object reference
<p>i have the follow lines of code that I am using to create a navigationview to load fragments and this android application. I am getting the error: <strong>android.support.v4.app.Fragment.mFragmentManager' on a null object reference</strong>. I created the fragments already and the navigationview works.</p>

<pre><code>public void selectDrawerItem(MenuItem menuItem){

    Fragment fragment = null;
    Class fragmentClass = null;

    switch(menuItem.getItemId()){
        case R.id.nav_show_all_events_activity:
            fragmentClass = AllEventsFragment.class;
            break;
        case R.id.nav_whats_hot_today_activity:
            fragmentClass = WhatsHotFragment.class;
            break;
    }

    try {
        fragment = (Fragment) fragmentClass.newInstance();
    } catch (Exception e) {
        e.printStackTrace();
    }

    FragmentManager fragmentManager = getSupportFragmentManager();
    fragmentManager.beginTransaction().replace(R.id.flContent, fragment).commit();

    menuItem.setChecked(true);
    setTitle(menuItem.getTitle());
    mDrawer.closeDrawers();
}
</code></pre>