I am trying to use the UserID from the Connection string from a datasource login as a parameter in a dataset to retrieve a group of codes by user at runtime. I want to force login for the datasource that is set up in SQLServer 2005 as we are using MAC's with no domain access as well as PC's in our enterprise. We are using Reporting Services 2005. Perhaps a UDF that parses this ID out of the connection string and returns it to the dataset query?