Help, I'm going nuts.

I have a challenge that is so far beating me. I have a pivot table that
summarises sales values and margins by month and I had no problem in adding a
calculated field with a monthly budget figure and charted this quite easily.

So far so good. However, I now need to break these numbers down by product
groups, but I can't get the calculated budget field to break down by product
group - I have tried using an IF statement in the calculated field but it
just returns the €˜false value (i.e. if, true, false). Also the total isnt
adding up, e.g. the budget part of the table resembles:

Month group a group b total
Jan 100 100 100
Feb etc.

The chart has gone from clear and simple to a techicolour nightmare €“ but
Ill worry about that when I have got the pivot table sorted.

Any help is much appreciated.

Regards,

Nigel