/// <summary>
/// Get the next available training sessions ordered by date.
/// </summary>
/// <returns>A collection of <see cref="TrainingSession"/>.</returns>
private IEnumerable <PictureTrainingSessionViewModel> GetAvailableTrainingSessions()
{
return(TrainingSessionService
.GetAllAvailable(int.Parse(Application.Current.Properties["UserId"].ToString()))
.OrderBy(s => s.Date));
}