Hope someone can help with this little problem. Whilst I know it is
more than achievable I just can't seem to get my head round the
code.

The worksheet updates from a data source providing details of back
orders. Column "A" contains the customer number, the data is also
sorted on the column. So for alternative customer number we want to
shade the background of those cells therefore making it easier to
read.

Whilst I can find many examples of shading alternate row, I can't find
any for alternative blocks.

Hope that makes sense.

Many thanks in advance

Alan