title: can't Get stream of mp3 file in wp7 application
body: <p>i'm building a wp7 application for a game using silverlight &amp; XNA 
   i have an mp3 file called  "<code>Punch1.mp3</code>" <code>(Build action : resource )</code>  stored inside a folder called "<code>SoundEffects"</code> inside the project folder</p>
  
  <p>and i want to play the file using this code  </p>
  
  <pre><code>         StreamResourceInfo info;
  
           Uri myuri = new Uri("/SoundEffects/Punch1.mp3", UriKind.Relative);
           info = App.GetResourceStream (myuri);
           punch1 = SoundEffect.FromStream(info.Stream ) ; 
  </code></pre>
  
  <p>punch is defined in the code here : </p>
  
  <pre><code>public static SoundEffect punch1;
  </code></pre>
  
  <p>the problem is that it raises a nullreference exception in the third line claiming that info is null 
  and that's true in the debugging mode , i found that the resource stream info is null<br>
  i think this is because the it can't read the file although the uri is correct </p>
  
  <p><img src="https://i.stack.imgur.com/q9nyx.png" alt="enter image description here"></p>