Asp – The incoming request does not match any route in My sample mvc application

Hai guys,
I started a new asp.net mvc application and i followed the steps given in
http://www.packtpub.com/article/your-first-asp.net-mvc-application

when i press F5 i got the error "The incoming request does not match any route"…
Any suggestions ….

Update:

 public static void RegisterRoutes(RouteCollection routes)
    {
        routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

        routes.MapRoute(
            "EmployeeShow",                    // Route name
            "Employee/{firstname}",            // URL with parameters
             new
             {                             // Parameter defaults
                 controller = "EmployeeController",
                 action = "Show",
                 firstname = ""
             }
        );

    }

My controller

public class EmployeeController : Controller
{
    //
    // GET: /Employee/

    public ActionResult Show(string firstname)
    {
        if (string.IsNullOrEmpty(firstname))
        {
            ViewData["ErrorMessage"] = "No firstname provided!";
        }
        else
        {
            Employee employee = new Employee
            {
                FirstName = firstname,
                LastName = "Example",
                Email = firstname + "@example.com"
            };

            ViewData["FirstName"] = employee.FirstName;
            ViewData["LastName"] = employee.LastName;
            ViewData["Email"] = employee.Email;
        }

        return View();
    }

}