I have a chart which uses source data from two worksheets (three sets of
values - two sets from one sheet, one from the other). I have set up named
ranges for the values and x-axis but when inputting 3rd set of values name
into values field of chart source data dialog box i get "invalid external
reference to worksheet" error. The first two sets of values work fine. I have
2 named x-axis ranges, one for each sheet, plus two period select named
ranges (countif(range, "<="&cellwith current month)) one for each sheet.

Unfortunately I cannot collate the ranges into one sheet as the format of
the report cannot be changed.

Any ideas?

Thanks

pb