setTitle method not working in Child Activity
<p>I'm new to Android development. Normally in any activity class, I just simply use <code>setTitle("My title")</code> at any place will do then the window title will change dynamically.</p>

<p>However, when I try using this method in child activity, it won't have any effect. When I try use Toast, Menu option it also no effect at all.</p>

<p>How can this be done?</p>
