//test the call history functionality
static void Main()
{
//Create a new mobile phone
GSM mobile = new GSM("Xperia", "Sony", 670.99, "Kitty");
//Get information about created mobile phone
mobile.ToString();
//Get information about static field iPhone
GSM.IPhone4S.ToString();
//Add calls and print
mobile.AddCalls(DateTime.Now, "+359 885 440 340", 1);
mobile.AddCalls(DateTime.Now, "+359 886 789 451", 94);
mobile.PrintCalls();
//Delete call and print
mobile.DeleteCalls(2);
mobile.PrintCalls();
//Calculate total price
mobile.CalculateFinalPrice(0.35);
//Clear calls and print
mobile.ClearCalls();
}