Field validation on product name

 Hi,

I'm trying to create a field validation that makes a picklist field required for specific products (in Opportunity Product Revenue).  The closest I've gotten is with the following: 

  

       ((FieldValue('<ProductName>')="Workshop") AND ([<plComponent_ITAG>] IS NOT NULL)) OR (FieldValue('<ProductName>')<>"Workshop")

I have this validation on both the Component field (picklist) and the Product ID field (since I can't do validation on the product field).  I'm not sure if I'm evaluating the product name properly because when I use just the first statement (before the OR) it evaluates as False for everything and always requires Component to be filled in and when I add the second statement, it doesn't trigger at all.