[rules-users] Using global in LHS

Hi, again a question, any body had success using globals in LHS? Following DSL [condition][]is a Item=Item() [condition][]-is of type Advertisment=advertisment contains catId rule when $pli: is a Item - is of type Advertisment then // do whatever you want end catId is a member of Item advertisment is a Integer[] array set as global comiling ends with: Unable to create Field Extractor for 'advertisment' of '[ClassObjectType It works fine if advertisment is a member of Item, but i want to have it as global ... Cheers Markus