Question about poseballs linked to furniture

Okay, say you have a couch with several poseballs linked to it. Most of them just have a sit pose, but one of them is supposed to do something else - give the av sitting on it a book.

An av sits on that poseball and receives the book. So far so good. But now when another av sits on one of the other poseballs, the change event gets triggered again and the first av gets offered another book.

Is there any economic way to prevent this, short of unlinking the poseballs?

In that poseball you want to store the key of the last sitter. Then you can offer the book only if there is a change (that is, the last recorded avatar on the sit target was NULL_KEY).

This other recent thread was about pretty much the same problem. In that case it was for starting and stopping a boat, but the solution is the same.

/54/b2/265500/1.html

Thanks! Got it sorted with your help