Thanks, that works just fine. I was on the right lines, but got a bit fixated about looking for a current row value, when I could have just generated a row number myself for this purpose!
My next issue, which is more of a niggle, but often data fields names are longer than their display area. Normally when this happens the data field name is clipped and shown with ... on the end but on the odd occasion the field does not do this and is shown across multiple lines (see attached), which then messes up the rest of the layout in design mode. What is causing this?
TIA,
David