A Message sent to all background groups when a card they are placed on is opened. If there is a message handler by the same name in the message path, then it will be executed.
The parameter <backgroundID> is the ID number of the background being opened.
on openBackground theBackgroundID -- update content of group end openBackground
on openBackground theBackgroundID if the short name of this card is "highscores" then show button "play again" end if end openBackground
Use the openBackground Message handler to change a group's objects, or perform other updates, when a card with the group on it is opened.
A group is only considered a background group if its backgroundBehavior property is set to true.