Error deploying CLR udf project in VS - system.core 3.5 not found in SQL catalog

I am building CLR Stored Procedures and UDFs as discussed in this article:

http://www.codeproject.com/KB/cs/CLR_Stored_Procedure.aspx

When I execute Build > Deploy, I get the following er开发者_如何学编程ror:

Error: Assembly 'system.core, version=3.5.0.0, culture=neutral, publickeytoken=b77a5c561934e089.' was not found in the SQL catalog.

Note that I am using some classes in .NET 3.5.

How can I fix this? I am deploying to Sql Server Express, but in prod it will be Sql Server 2005.

Here's the answer:

http://weblogs.asp.net/paulomorgado/archive/2009/06/13/playing-with-sql-server-clr-integration-part-iv-deploying-to-sql-server-2005.aspx