// Reference : http://www.geekchamp.com/tips/all-about-wp7-isolated-storage-store-data-in-isolatedstoragesettings
 /// <summary>
 /// Saves the logged user.
 /// </summary>
 /// <param name="user">The user.</param>
 /// <returns></returns>
 public bool SaveLoggedUser(User user)
 {
     if ((user != null) && (!user.HasNullOrEmpty()) && (!settings.Contains(userKeyword)))
     {
         Debug.WriteLine(DebugInfo.Format(DateTime.Now, this, MethodInfo.GetCurrentMethod(), String.Format("Adding user {0} to storage.", user.username)));
         settings.Add(userKeyword, user);
         // TDOD Localize string
         OnUserChanged(new ApplicationEventArgs(String.Format("User {0} has been saved.", user.username), ApplicationError.SUCCESS));
         return true;
     }
     return false;
 }
 /// <summary>
 /// Retrives the logged user.
 /// </summary>
 /// <returns></returns>
 public User RetriveLoggedUser()
 {
     Debug.WriteLineIf(!settings.Contains(userKeyword), DebugInfo.Format(DateTime.Now, this, MethodInfo.GetCurrentMethod(), "IsolatedStorageSettings does NOT contain user."));
     Debug.WriteLineIf(!settings.Contains(userKeyword), DebugInfo.Format(DateTime.Now, this, MethodInfo.GetCurrentMethod(), "IsolatedStorageSettings DOES contain user."));
     User user = new User();
     if (settings.Contains(userKeyword))
     {
         settings.TryGetValue<User>(userKeyword, out user);
     }
     return user;
 }