title: Can't play a sound with an UIAlertView
body: <p>A part of my tweak must play a sound and display an UIAlertView when a certain message is received. Then when the UIAlertView is cancelled, the sound stops. </p>
  
  <p>At the moment, the UIAlertView shows up, but the sound is not played. Here is my code</p>
  
  <pre><code>#define url(x) [NSURL URLWithString:x]
  
  UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Title" message:@"message" delegate:nil cancelButtonTitle:@"Ok" otherButtonTitles:nil]; 
  
  AVAudioPlayer *mySound;
  mySound = [[AVAudioPlayer alloc] initWithContentsOfURL:url(@"/Library/Ringtones/Bell Tower.m4r") error:nil];
  
  
  [mySound setNumberOfLoops:-1];  
  [mySound play];
  
  [alert show]; 
  [alert release];
  [mySound stop];
  [mySound release];
  </code></pre>