private void LoadSource()
 {
     using (IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
     {
         using (IsolatedStorageFileStream fileStream = myIsolatedStorage.OpenFile(MediaSource, FileMode.Open, FileAccess.Read))
         {
             MediaPlayerElement.SetSource(fileStream);
         }
     }
 }