Getting error after upgrade to 2010 .NET 4

Hi I am getting an error mesage about my membership I have included System.Web.ApplicationServices



Error    2    Type 'System.Web.Security.MembershipUser' in assembly 'System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' has been forwarded to assembly 'System.Web.ApplicationServices'. Either a reference to 'System.Web.ApplicationServices' is missing from your project or the type 'System.Web.Security.MembershipUser' is missing from assembly 'System.Web.ApplicationServices'.    C:\Users\###\Documents\Visual Studio 2010\JobTracker\users\NewJob.aspx.vb    82    29    C:\...\JobTracker\


do I need to amend my web.config file


thanks
M

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