Good evening. As discussed at the conference, here's a more succinct way to express this simple requirement. Perhaps discriminator's motivating example should be more complex. Comments and corrections welcome, Simon Simon Parker Software Consultant PolarLake 80 Harcourt Street Dublin 2, Ireland Phone +353 1 449-1075 Fax +353 1 449-1011 Web http://www.polarlake.com/ The information transmitted in this email is intended for the addressee only and may contain confidential and/or privileged material. Any review, retransmission, dissemination, reliance upon or other use of this information by persons or entities other than the addressee is prohibited. If you think, for any reason, that this message may have been addressed to you in error, we would ask you to notify the sender immediately by return email and delete the material. PolarLake Limited | Registered in Dublin, Ireland | Number 357324 | Registered office as above.