how to turn off phone ringer for incoming calls?
<p>How does one turn off phone ringer for incoming calls? Can this be done programmatically? Right now I am using below code but it's not working:</p>

<pre><code>AudioManager am = (AudioManager)getSystemService(Context.AUDIO_SERVICE);
                am.setRingerMode(AudioManager.RINGER_MODE_SILENT);
</code></pre>
