role based security in asp.net using windows authentication problem

im trying to convert this tutorial in asp.net c#
http://weblogs.asp.net/scottgu/pages/Recipe_3A00_-Implementing-Role_2D00_Based-Security-with-ASP.NET-2.0-using-Windows-Authentication-and-SQL-Server.aspx
but im getting some errors with regards in this part:
in the global.asax
Roles.AddUsersToRole("Domain\UserName","Admins");
the error says that "unrecognized escape sequence"
ive tried using "@" or "//" to solve my problem but it didn't help me
i also have a problem with this part:

PopulateRoleList()

UpdateRolesFromList()
its a vb code in asp.net that's why i use a conver ...