Many thanks to everyone for your advice on this issue. Catherine ----------------------------------------------------------------------------------------------------------------- The information contained in this message is confidential and is intended for the addressee only. If you have received this message in error or there are any problems please notify the originator immediately. The unauthorised use, disclosure, copying or alteration of this message is strictly forbidden. This mail and any attachments have been scanned for viruses prior to leaving Barts & The London NHS Trust network. Barts & The London NHS Trust will not be liable for direct, special, indirect or consequential damages arising from alteration of the contents of this message by a third party or as a result of any virus being passed on. -----------------------------------------------------------------------------------------------------------------