static void Main(string[] args)
{
//SpeechSynthesizer synth = new SpeechSynthesizer();
//synth.Speak("Hello Yasaman This is the grade book program");
GradeBook book = new GradeBook();
book.NameChanged += new NameChangedDelegate(OnNameChanged);
book.Name = "Yasaman's Grade Book";
book.Name = "Yasi's book";
book.AddGrade(91);
book.AddGrade(89.5f);
book.AddGrade(75);
GradeStatistics stat = book.ComputeSatistics();
Console.WriteLine(book.Name);
WriteResult("Average", stat.AverageGrade);
WriteResult("Highest Grade", (int)stat.HighetGrade);
WriteResult("Lowest Grade", stat.LowestGrade);
Console.ReadLine();
}