title: TelephonyManager.getLine1Number() failing?
body: <p>I want to get phone number of android device. I use this code:</p>
  
  <pre><code>TelephonyManager tm = (TelephonyManager)this.getApplicationContext().getSystemService(Context.TELEPHONY_SERVICE); 
  String phoneNumber=  tm.getLine1Number();
  </code></pre>
  
  <p>On my phone (HTC Wildfire) I can not get phone number - all I get is empty string. If I run code on emulatur, phone number is normally showed.</p>
  
  <p>If I go to Settings=>About phone=>Phone identity->Phone number, phone number is "Unknown". </p>
  
  <p>Where is the problem? Is something wrong with my SIM?</p>