I am looking for a way to conditionally prompt for a parameter or input from the user based on values existing in the report dataset.  For example, if the value of {ShipHead.ShipVia} = '*Third Party*', I want the report user to select a carrier from a dropdown list.  However, if {ShipHead.ShipVia} <> '*ThirdParty*', I don't want the user prompted to make any selection.