public static void Main()
{
Employee o1 = new Employee("Amol", 12346555, 1015);
Employee o2 = new Employee("Amol", 123465);
Employee o3 = new Employee("Amol");
Employee o4 = new Employee();
Console.WriteLine(o1.toString());
Console.WriteLine(o2.toString());
Console.WriteLine(o3.toString());
Console.WriteLine(o4.toString());
Console.WriteLine(o1.EmpNo);
Console.WriteLine(o2.EmpNo);
Console.WriteLine(o3.EmpNo);
Console.WriteLine(o3.EmpNo);
Console.WriteLine(o2.EmpNo);
Console.WriteLine(o1.EmpNo);
}