Thanks for all your replies.

Unfortunately, I've tried everything you people suggested and nothing worked.So, I've kind of given up on it for now.

What I'm doing now is to retrieve all combinations of item code and item stock, and store these in a hash table. This way I can query the hash table later on.

Not the best way to do I know, but I've spent a few days on this issue and need to move on.

Thanks for all your inputs anyway.