Alistair, mainly because this type of program is developed by 'orrible snotty little teenagers who think Java, animated thingies on web pages etc are "Cool" but who's communication with humans is usually limited to "Cool" and "Duh". They think all Barbara described is totally obvious and it would never occur to them that it might need explanation.

Believe me, I've got two off them! (Well actually they outgrown that stage now, but the memory lingers)

Pete M