I have a crystal report with a parameter for the production line. I am running the report with ASP.NET, and using Crystal to pull the data. I can specify the parameter to pass into Crystal ok, but what is the best way to make it so the user can choose all production lines or a specific production line. Right now I am passing in the specific value let's say 100, and then a blank if they want all production lines. How do I use the select expert to limit the values for the production line to be a specific value (example 100) or to return data for all production lines if the value is blank?