{ Code: Impossible }

    public class UsersController : Controller
    {

        List<string> users = new List<string> ()
            {
                "mace.windu",
                "yoda",
                "senator.amidala",
                "anakin.skywalker",
                "obiwan.kenobi"
            };

        public ActionResult Index()
        {
            return View( users );
        }


        [HttpPost]
        public ActionResult Delete ( string[] userstodelete )
        {

            if ( userstodelete == null || userstodelete.Length == 0 )
            {
                throw new ArgumentException ( 
                    "argument must contain at least one entry", 
                    "userstodelete" );
            }

            // code could go here to
            // call out to some service to
            // delete these users

            TempData["deletedUsers"] = userstodelete;

            foreach ( var user in userstodelete )
                users.Remove ( user );

            return View ("Index", users);
        }
    }