Thanks for all the pointers. I'll have a look. I did reply earlier, but the "reply to" is broken: it sent to the OP rather than the list... Perhaps there is a lesson in newbie navigation for the website here. -Nigel ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to majordomo@xxxxxxxxxxxxxx so that your message can get through to the mailing list cleanly