DotNetNuke Silverlight 3.0 Hello World

<%@ WebService Language="C#" Class="HelloWorld3.WebService" %>

using System.Web.Services;
using DotNetNuke.Entities.Users;

namespace HelloWorld3
{
    [WebService(Namespace = "http://ADefWebserver.com/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    public class WebService : System.Web.Services.WebService
    {
        #region GetUsername()
        [WebMethod]
        public string GetUsername()
        {
            string strUsername = "World!";

            // Get the current user 
            UserInfo objUserInfo = UserController.GetCurrentUserInfo();

            // If the user is not -1 they are logged in
            if (objUserInfo.UserID > -1)
            {
                strUsername = objUserInfo.DisplayName;
            }

            return strUsername;
        }
        #endregion
    }
}