Write a program in C# for Custom Exception

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

namespace ConsoleApplication9
{
    class customexception:Exception
    {
        static void checkname(string str)
        {
            if (str.Contains('@') || str.Contains('$'))
            {
                throw new customexception();
                Console.WriteLine("invalid name ");
            }
            else
            {
                Console.WriteLine("valid name"+str);
            }
        }
        static void Main(string[] args)
        {
            string name;
            Console.WriteLine("enter name");
            name = Console.ReadLine();
            try
            {
                checkname(name);
            }
            catch (customexception ex)
            {
                Console.WriteLine(ex.Message);
            }
            finally
            {  Console.WriteLine("Programend”);}
}}}







OUTPUT
Enter name
MICROSOFT
Valid nameMICROSOFT