Notes/Domino 4 and 5 Forum

I have been searching here for 2 days to not look stupid and I do not understand what is
wrong with my syntax for this full text search. I appreciate any help I can get on this one.

Set dc = db.ftsearch( {Form = "Lookup Samples" AND FIELD Product_ID = "" } , 0)

I keep getting query not understandable. Not sure why. It seems pretty straight forward.

Thanks.