Using IEnumerator and IEnumerable in the .NET Framework

In this post I actually created a simple program using C# that implements IEnumerator and IEnumerable.
So if you are interested let's get started....

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;
namespace IEnumSamp
{
    class Program
    {
        static void Main(string[] args)
        {

            clsEmployee[] emp = new clsEmployee[]
            {   new clsEmployee("rhian", "calzado", 30),
                new clsEmployee("jin", "necesario", 29),
                new clsEmployee("rouie", "andes", 30)
            };

            EmployeeCollection myEmployees = 
                        new EmployeeCollection(emp);

            IEnumerator EmpEnum = myEmployees.GetEnumerator();

            while (EmpEnum.MoveNext())
            {
                Console.WriteLine(((clsEmployee)(EmpEnum.Current)).FirstName);
            }

            foreach (clsEmployee emp_ in myEmployees)
            {
                Console.WriteLine(emp_.ToString());
            }
        }
    }
}

using System;
using System.Collections.Generic;
using System.Collections;
using System.Linq;
using System.Text;

namespace IEnumSamp
{
    public class clsEmployee
    {
        private string strFirstName;
        private string strLastName;
        private int intAge;

        public clsEmployee(string fname, string lname, int age)
        {
            this.strFirstName = fname;
            this.strLastName = lname;
            this.intAge = age;
        }

        public string FirstName
        {
            get
            {
                return this.strFirstName;
            }
        }

        public string LastName
        {
            get
            {
                return this.strLastName; 
            }
        }

        public int Age
        {
            get
            {
                return this.intAge;
            }
        }

        public override string ToString()
        {
            return "Fullname: " + this.strLastName + ", " + this.strFirstName + " Age: " +this.intAge.ToString ();

        }
    }

    public class EmployeeCollection : IEnumerable
    {
        private clsEmployee[] emp_;

        public EmployeeCollection(clsEmployee[] emp)
        {
            if (emp.GetType() == typeof(clsEmployee[]))
            {
                emp_ = emp;
            }
            else
                throw new ArgumentException("invalid type");
        }

        #region IEnumerable Members

        public IEnumerator GetEnumerator()
        {
            return (IEnumerator)new EmployeeEnum(emp_);
        }

        #endregion
    }

    public class EmployeeEnum : IEnumerator
    {
       private clsEmployee[] empList = null;

       public EmployeeEnum(clsEmployee[] emp)
       {
           if (emp.GetType() == typeof(clsEmployee[]))
           {
               empList = emp;
           }
           else
               throw new ArgumentException("invalid type");
       }

       private int intPosition=-1;

        #region IEnumerator Members

        public object Current
        {
            get 
            {
                if (intPosition < 0)
                    throw new InvalidOperationException();
                if (intPosition > empList.Length)
                    throw new InvalidOperationException();

                    return empList[intPosition];
            }
        }

        public bool MoveNext()
        {
            this.intPosition++;

            if (this.intPosition >= empList.Length)
                return false;
            else
                return true;
        }

        public void Reset()
        {
            this.intPosition = -1;
        }

        #endregion
    }

}