title: What is onCreateOptionsMenu(Menu menu)
body: <p>What are the two parameters Menu and menu in method <code>onCreateOptionsMenu(Menu menu)</code> and how to use this method. 
  I have another question why <code>this</code> parameter is used in </p>
  
  <pre><code>Intent intent = new Intent(this, DisplayMessageActivity.class);
  </code></pre>